γ-MnO2 nanorobs and Au/γ-MnO2 catalysts were synthesized and characterized by the X-ray powder diffraction XRD the scanning electron microscope SEM and transmission electron microscope TEM . The characterizations sh...γ-MnO2 nanorobs and Au/γ-MnO2 catalysts were synthesized and characterized by the X-ray powder diffraction XRD the scanning electron microscope SEM and transmission electron microscope TEM . The characterizations show that Au particles are well dispersed on the surface of γ-MnO2 nanorobs with a particle size of about 10 nm.The catalytic performance is evaluated in solvent-free toluene oxidation with oxygen. The influences of several process parameters such as reaction time reaction temperature initial oxygen pressure and catalyst amounts on the catalytic performance are studied.Catalytic results reveal that Au/γ-MnO2 catalyst has a unique selectivity to benzaldehyde and all these factors greatly influence the conversion of toluene and selectivity of bezaldehyde benzoic acid and benzyl benzoate.However these factors have slight influence on the selectivity of benzyl alcohol.展开更多
The catalytic oxidation of toluene over Ag/SBA‐15synthesized under different pretreatment conditions,including O2at500°C(denoted O500),H2at500°C(H500),and O2at500°C followed by H2at300°C(O500‐H30...The catalytic oxidation of toluene over Ag/SBA‐15synthesized under different pretreatment conditions,including O2at500°C(denoted O500),H2at500°C(H500),and O2at500°C followed by H2at300°C(O500‐H300)was studied.The pretreated samples were investigated by N2physisorption,X‐ray diffraction,and ultraviolet‐visible diffuse reflectance.The pretreatment atmosphere greatly influences the status of the Ag and O species,which in turn significantly impacts the adsorption and catalytic removal of toluene.Ag2O and amorphous Ag particles,as well as a large amount of subsurface oxygen species,are formed on O500,and the subsurface oxygen enhances the interaction between Ag species and toluene,so O500shows good activity at higher temperature.However,its activity at lower temperature is not as high as expected,with a reduced presence of Ag2O and lower adsorption capacity for toluene.H2pretreatment at500°C is conducive to the formation of large Ag particles and yields the largest adsorption capacity for toluene,so H500exhibits the best activity at lower temperatures;however,because of poor interaction between Ag and toluene,its activity at higher temperature is modest.The O500‐H300sample exhibits excellent catalytic activity during the whole reaction process,which can be attributed to the small and highly dispersed Ag nanoparticles as well as the existence of subsurface oxygen.展开更多
Herein,a bottom-down design is presented to successfully fabricate ZIF-derived Co3O4,grown in situ on a one-dimensional(1D)α-MnO2 material,denoted as α-MnO2@Co3O4.The synergistic effect derived from the coupled inte...Herein,a bottom-down design is presented to successfully fabricate ZIF-derived Co3O4,grown in situ on a one-dimensional(1D)α-MnO2 material,denoted as α-MnO2@Co3O4.The synergistic effect derived from the coupled interface constructed betweenα-MnO2 and Co3O4 is responsible for the enhanced catalytic activity.The resultantα-MnO2@Co3O4 catalyst exhibits excellent catalytic activity at a T90%(temperature required to achieve a toluene conversion of 90%)of approximately 229℃,which is 47 and 28℃ lower than those of the pureα-MnO2 nanowire and Co3O4-b obtained via pyrolysis of ZIF-67,respectively.This activity is attributed to the increase in the number of surface-adsorbed oxygen species,which accelerate the oxygen mobility and enhance the redox pairs of Mn^4+/Mn^3+ and Co^2+/Co^3+.Moreover,the result of in situ diffuse reflectance infrared Fourier transform spectroscopy suggests that the gaseous oxygen could be more easily activated to adsorbed oxygen species on the surface of α-MnO2@Co3O4 than on that of α-MnO2.The catalytic reaction route of toluene oxidation over theα-MnO2@Co3O4 catalyst is as follows:toluene→benzoate species→alkanes containing oxygen functional group→CO2 and H2O.In addition,the α-MnO2@Co3O4 catalyst shows excellent stability and good water resistance for toluene oxidation.Furthermore,the preparation method can be extended to other 1D MnO2 materials.A new strategy for the development of high-performance catalysts of practical significance is provided.展开更多
Co-based catalysts are the most promising catalysts in catalytic oxidation of volatile organic compounds(VOCs).Precious metal doping is adopted to improve the catalytic activity of toluene on Co_(3)O_(4) catalysts,but...Co-based catalysts are the most promising catalysts in catalytic oxidation of volatile organic compounds(VOCs).Precious metal doping is adopted to improve the catalytic activity of toluene on Co_(3)O_(4) catalysts,but greatly increases its cost along with it.It is found that doping a small amount of rare earth(Ce,Pr,Sm and Nd)can dramatically promote the catalytic activity of Co_(3)O_(4).Especially,the Nd-doped Co_(3)O_(4) catalyst exhibits excellent catalytic activity with a toluene removal rate of 90% at 162.1℃,which is even better than that of Pt-doped Co_(3)O_(4).Compared with other rare earth metal doping,the Nd doping leads to a higher ratio of Co^(3+)/Co^(2+) and has more oxygen vacancies.The in situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)experiments show that the lattice oxygen of Nd-Co sample can be utilized at a quite low temperature,while that of pure Co_(3)O_(4) cannot engage in oxidation reaction when the temperature is below 200℃,which visually demonstrates the main reason for the improved catalytic performance of Nd-Co catalyst.展开更多
In this study,K_(x)-Mn-Ce catalysts prepared by sol-gel method were investigated for toluene oxidation.Compared with Mn-Ce,the catalytic performance of K_(x)-Mn-Ce was further improved.X-ray diffraction(XRD),high reso...In this study,K_(x)-Mn-Ce catalysts prepared by sol-gel method were investigated for toluene oxidation.Compared with Mn-Ce,the catalytic performance of K_(x)-Mn-Ce was further improved.X-ray diffraction(XRD),high resolution transmission electron microscopy(HRTEM)and Raman analyses demonstrate that K ions enter the lattice of CeO_(2) and disperse uniformly.The results of X-ray photoelectron spectroscopy(XPS),H_(2)-temperature programmed reduction(H_(2)-TPR).and O_(2)-temperature programmed desorption(O_(2)-TPD)analyses indicate that there is a strong interaction between K,Mn and Ce;the charge co mpensation effect would be induced when K ions enter the lattice of CeO_(2),which leads to more oxygen vacancies due to the generation of more Ce^(3+).Toluene-TPD shows that K-doping enhances the activation ability of toluene.Among all catalysts,K0.1-Mn-Ce shows the highest concentration of Mn^(4+),Ce^(3+),Osur,and redox ability,resulting in higher low-temperature catalytic activity.Additionally,the results of stability and water resistance also prove that K0.1-Mn-Ce catalyst possesses excellent stability and water resistance.展开更多
A series of monolithic MnO_(2)/iron mesh (IM) catalysts for oxidation of toluene were successfully prepared by using in situ hydrothermal growth.MnO_(2)can grow firmly on the IM substrates surface with a shedding rate...A series of monolithic MnO_(2)/iron mesh (IM) catalysts for oxidation of toluene were successfully prepared by using in situ hydrothermal growth.MnO_(2)can grow firmly on the IM substrates surface with a shedding rate of only 0.14%.Due to the highest O_(ads) and high-valent Mn^(4+) and Fe^(3+) elements,the temperature at 50% and 90% toluene conversion (T_(50%) and T_(90%)) was 252 and 265℃,respectively for the best performance catalyst (hydrothermal temperature of 80℃,hydrothermal time of 12 h,and precursor manganese ion concentration of 0.03 mol/L).The catalysts also presented good water resistance and cycle performance.In-situ DRIFTS results suggesting that toluene was first rapid transformed into the reaction intermediate species (benzoate species) and then converted to CO_(2)and H_(2)O.Therefore,this work provides a new direction for the research and application of IM-based monolithic catalysts.展开更多
The cryptomelane-type manganese oxide (OMS-2)-supported Co (x Co/OMS-2;x=5,10,and15 wt.%) catalysts were prepared via a pre-incorporation route.The as-prepared materials were used as catalysts for catalytic oxidation ...The cryptomelane-type manganese oxide (OMS-2)-supported Co (x Co/OMS-2;x=5,10,and15 wt.%) catalysts were prepared via a pre-incorporation route.The as-prepared materials were used as catalysts for catalytic oxidation of toluene (2000 ppmV).Physical and chemical properties of the catalysts were measured using the X-ray diffraction (XRD),Fourier transform infrared spectroscopic (FT-IR),scanning electron microscopic (SEM),X-ray photoelectron spectroscopy (XPS),and hydrogen temperature-programmed reduction (H_(2)-TPR)techniques.Among all of the catalysts,10Co/OMS-2 performed the best,with the T90%,specific reaction rate at 245℃,and turnover frequency at 245℃ (TOFCo) being 245℃,1.23×10^(-3)moltoluene/(gcat·sec),and 11.58×10^(-3)sec-1for toluene oxidation at a space velocity of 60,000mL/(g·hr),respectively.The excellent catalytic performance of 10Co/OMS-2 were due to more oxygen vacancies,enhanced redox ability and oxygen mobility,and strong synergistic effect between Co species and OMS-2 support.Moreover,in the presence of poisoning gases CO_(2),SO_(2)or NH_(3),the activity of 10Co/OMS-2 decreased for the carbonate,sulfate and ammonia species covered the active sites and oxygen vacancies,respectively.After the activation treatment,the catalytic activity was partly recovered.The good low-temperature reducibility of 10Co/OMS-2 could also facilitate the redox process accompanied by the consecutive electron transfer between the adsorbed O_(2)and the cobalt or manganese ions.In the oxidation process of toluene,the benzoic and aldehydic intermediates werefirst generated,which were further oxidized to the benzoate intermediate that were eventually converted into H_(2)O and CO_(2).展开更多
La_(1-x)CoO_(3-δ)catalysts with different non-stoichiometry of lanthanum ions were synthesized by using the sol-gel method,and their catalytic performance in toluene combustion was investigated.The results showed tha...La_(1-x)CoO_(3-δ)catalysts with different non-stoichiometry of lanthanum ions were synthesized by using the sol-gel method,and their catalytic performance in toluene combustion was investigated.The results showed that the catalytic activity and stability of A-site nonstoichiometric La_(1-x)CoO_(3-δ)were improved to a certain extent compared with pure LaCoO_(3)perovskite.Among them,the La_(0.9)CoO_(3-δ)catalyst gave the best catalytic performance for toluene oxidation.It achieved 90%toluene conversion at 205℃under the conditions of a WHSV(weight hourly space velocity)of 22,500 mL/(g·hr)and a 500 ppmV-toluene concentration.Various characterization techniques were used to investigate the relationship between the structure of these catalysts and their catalytic performance.It was found that the non-stoichiometric modification of the lanthanum ion at position A in LaCoO_(3)changed the surface element state of the catalyst and increased the oxygen vacancy content,thus,combined with improved reducibility,improving toluene degradation on the catalyst.展开更多
The selective oxidation of toluene and its derivatives is extremely important in the chemical industry.The use of photocatalysis in organic synthesis has attracted considerable attention among synthetic chemists becau...The selective oxidation of toluene and its derivatives is extremely important in the chemical industry.The use of photocatalysis in organic synthesis has attracted considerable attention among synthetic chemists because of its ＂green＂ environmental characteristics.In this study,nanoscale Bi_2WO_6with a flower-like morphology was found to be a highly efficient photocatalyst in the catalytic oxidation of toluene and its derivatives using O_2 as the oxidant.The loading of Pd nanoparticles as a cocatalyst onto the flower-like Bi_2WO_6 was found to produce a significant enhancement in the catalytic activity.Mechanistic investigation showed that the superior performance of Pd/Bi_2WO_6 could be attributed to the improvement of both the reductive and oxidative abilities of Bi_2WO_6 by the loading of the cocatalyst.展开更多
The plane exposure of support vitally affects the catalytic performance of the catalyst.In this work,CeO_(2)nanorods((110)plane exposure),nano-octahedrons((111)plane exposure)and nano-cubes((100)plane exposure)were pr...The plane exposure of support vitally affects the catalytic performance of the catalyst.In this work,CeO_(2)nanorods((110)plane exposure),nano-octahedrons((111)plane exposure)and nano-cubes((100)plane exposure)were prepared as the supports of Pt/CeO_(2)samples to investigate the effect of CeO_(2)plane exposure on total toluene oxidation.Characterizations reveal that the(110)plane of CeO_(2)is more helpful to the dispersion of Pt species,followed by(111)face.The improved dispersion of Pt species can enhance the metal-supports interaction,which promotes the electron transfer of CeO_(2)carrier to Pt nanoparticles and the adsorption-activation of O_(2),thereby facilitating the total oxidation of toluene via the Langmuir-Hinshelwood(L-H)mechanism.Therefore,Pt/CeO_(2)-r(nanorods)sample expresses excellent catalytic performance of toluene oxidation.Finally,the procedure of toluene total oxidation was studied by in-situ diffuse reflectance infrared Fourier transform(DRIFT)spectroscopy.We expect that this work can contribute to the development of an effective sample for the decomposition of volatile organic compounds(VOCs).展开更多
A series of hexadecylphosphate acid(HDPA) terminated mixed-oxide nanoparticles have been investigated to catalyze the oxidation of toluene exclusive to benzaldehyde under mild conditions in an emulsion of toluene/wate...A series of hexadecylphosphate acid(HDPA) terminated mixed-oxide nanoparticles have been investigated to catalyze the oxidation of toluene exclusive to benzaldehyde under mild conditions in an emulsion of toluene/water with the catalysts as stabilizers. With the HDPA-Fe2 O3/Al2 O3 as the basic catalyst, a series of transition metals, such as Mn, Co, Ni, Cu, Cr, Mo, V, and Ti, was respectively doped to the basic catalyst to modify the performance of the catalytic system, in expectation of influencing the mobility of the lattice oxygen species in the oxide catalysts. Under normally working conditions of the catalytic system, the nanoparticles of catalysts located themselves at the interface between the oil and water phases, constituting the Pickering emulsion. Both the doped iron oxide and its surface adsorbed hexadecylphosphate molecules were essential to the catalytic system for excellent performances with high toluene conversions as well as the exclusive selectivity to benzaldehyde. Under optimal conditions, ~83% of toluene conversion and >99% selectivity to benzaldehyde were obtained, using molecular oxygen as oxidant and HDPA-(Fe2 O3-Ni O)/Al2 O3 as the catalyst. This process is green and low cost to produce high quality benzaldehyde from O2 oxidation of toluene.展开更多
A facile hydrothermal method was applied to gain stably and highly efficient CuO-CeO_(2)(denoted as Cu1Ce2)catalyst for toluene oxidation.The changes of surface and inter properties on Cu1Ce2 were investigated compari...A facile hydrothermal method was applied to gain stably and highly efficient CuO-CeO_(2)(denoted as Cu1Ce2)catalyst for toluene oxidation.The changes of surface and inter properties on Cu1Ce2 were investigated comparing with pure CeO_(2)and pure CuO.The formation of Cu-Ce interface promotes the electron transfer between Cu and Ce through Cu^(2+)+Ce^(3+)↔Cu^(+)+Ce^(4+)and leads to high redox properties and mobility of oxygen species.Thus,the Cu1Ce2 catalyst makes up the shortcoming of CeO_(2)and CuO and achieved high catalytic performance with T_(50)=234°C and T_(99)=250°C(the temperature at which 50%and 90%C_(7)H_(8)conversion is obtained,respectively)for toluene oxidation.Different reaction steps and intermediates for toluene oxidation over Cu1Ce2,CeO_(2)and CuO were detected by in situ DRIFTS,the fast benzyl species conversion and preferential transformation of benzoates into carbonates through C=C breaking over Cu1Ce2 should accelerate the reaction.展开更多
In this paper, KMnO4 was used to pre-treat Co3 Fe-layered double hydroxides(LDH) precursor to prepare MnO2 decorated Co3Fe1Ox catalyst. The toluene oxidation performance of the catalyst was investigated systematically...In this paper, KMnO4 was used to pre-treat Co3 Fe-layered double hydroxides(LDH) precursor to prepare MnO2 decorated Co3Fe1Ox catalyst. The toluene oxidation performance of the catalyst was investigated systematically. The optimized 0.1 Mn CF-LDO catalyst exhibited the best catalytic performance, and the temperatures of 50% and 90% toluene conversion( T50 and T90) were 218 and 243 ℃, respectively. The apparent activation energy( Ea) was 31.6 k J/mol. The characterization results showed that the pre-redox reaction by KMnO4 could increase the specific surface area, Co^3+ species amount and oxygen defect concentration of the catalyst, which are the main reason of the improved toluene catalytic activity. Besides, this method was also applied to enhance toluene oxidation of iron mesh based monolithic catalyst. The 0.1 Mn CF-LDO/Iron mesh(IM) catalyst showed a 90% toluene conversion at around 316 ℃ which was much lower than that of without MnO2 addition(359 ℃). In addition, the water resistant of all the catalysts was studied as well, all the samples showed relatively good water resistance. The toluene conversion still remained to be over > 80% even in the presence of 10 vol.% water vapor.展开更多
We deposited NiO via atomic layer deposition on mesoporous SiO2 particles with diameters of several hundred micrometers and a mean mesopore size of -14 nm.NiO was deposited within the shell region of mesoporous SiO2 p...We deposited NiO via atomic layer deposition on mesoporous SiO2 particles with diameters of several hundred micrometers and a mean mesopore size of -14 nm.NiO was deposited within the shell region of mesoporous SiO2 particles with a shell thickness of -11 mm.We annealed the as-prepared NiO/SiO2 at 450 and 600℃,respectively.These two samples were used as catalysts for the uptake of toluene molecules and their oxidative conversion to CO2.The sample annealed at450℃ was generally more reactive in toluene uptake and its subsequent conversion to CO2.When the NiO/SiO2 annealed at 450℃ was exposed to toluene vapor at 160℃ and then heated to 450℃,CO2 was emitted with almost no toluene desorption.We suggest that our catalysts can be used as building blocks for odor removal devices that operate below 200℃.These catalysts can be regularly regenerated at -450℃.展开更多
The selective catalytic oxidation of toluene with hydrogen peroxide over V-Mo-based catalysts under mild conditions was studied.The promotion effect of Mo on the catalysts was studied with V/Al2O3 and Mo/Al2O3 as refe...The selective catalytic oxidation of toluene with hydrogen peroxide over V-Mo-based catalysts under mild conditions was studied.The promotion effect of Mo on the catalysts was studied with V/Al2O3 and Mo/Al2O3 as reference samples.The catalysts were characterized by XRD,TPR,and XPS techniques.The results show that the addition of Mo to V/Al2O3 may change the distribution of V species on Al2O3 surface.Over V-Mo/Al2O3 catalyst,highly dispersed amorphous V species facilitates benzaldehyde formation,and crystalline V2O5 species increases the conversion of toluene but decreases the selectivity to benzaldehyde,while AlVMoO7 species favors both the conversion of toluene and the formation of cresols.The yield of benzaldehyde depends remarkably on the surface O/Al and Mo/V atomic ratios,and gets to a maximum value of 13.2% with a selectivity of 79.5% at an O/Al atomic ratio of 3.0 and Mo/V atomic ratio of 0.7.展开更多
Mesoporous carbon-supported cobalt （Co-MC） catalysts are widely applied as electrode materials for bat- teries. Conversely, the development of Co-MC as bifunctional catalysts for application in organic catalytic rea...Mesoporous carbon-supported cobalt （Co-MC） catalysts are widely applied as electrode materials for bat- teries. Conversely, the development of Co-MC as bifunctional catalysts for application in organic catalytic reactions and degradation of water contaminants is slower. Herein, the catalyst displayed high activity in the selective oxidation of toluene to benzaldehyde under mild conditions, attaining a high selectivity of 92.3%. Factors influencing the catalytic reaction performance were also investigated. Additionally, Co-MC displayed remarkable catalytic activity in degrading dyes relative to the pure metal counterpart. Moreover, the catalyst exhibited excellent reusability, as determined by the cyclic catalytic experiments. The paper demonstrates the potential of Co-MC as a bifunctional catalyst for both toluene selective oxidation and water contaminant degradation.展开更多
Herein,Na^(+)and Ca^(2+)are introduced to MnO_(2)through cation-exchange method.The presence of Na^(+)and Ca^(2+)significantly enhance the catalytic activity of MnO_(2)in toluene oxidation.Among them,the Ca-MnO_(2)cat...Herein,Na^(+)and Ca^(2+)are introduced to MnO_(2)through cation-exchange method.The presence of Na^(+)and Ca^(2+)significantly enhance the catalytic activity of MnO_(2)in toluene oxidation.Among them,the Ca-MnO_(2)catalyst exhibits the best catalytic activity(T_(50)=194℃,T_(90)=215℃,E_a=57.2 k J/mol,reaction rate 8.40×10^(-10)mol/(sec·m^(2))at 210℃.T_(50)and T_(90):the temperature of 50%and 90%toluene conversion;E a:apparent activation energy)and possess high tolerance against 2.0 vol.%water vapor.Results reveal that the increased acidic sites of the MnO_(2)sample can enhance the adsorption of gaseous toluene,and the mobility of oxygen species and the content of reactive oxygen species in the catalyst are significantly improved due to the formed oxygen vacancy.Thus these two factors result in excellent catalytic performance for toluene oxidation combining with the weak CO_(2)adsorption ability.展开更多
The octahedral molecular sieve(OMS-2)-supported Fe( xFe/OMS-2: x = 1, 3, 5, and 10) catalysts were prepared using the pre-incorporation method. Physicochemical properties of the as-synthesized materials were character...The octahedral molecular sieve(OMS-2)-supported Fe( xFe/OMS-2: x = 1, 3, 5, and 10) catalysts were prepared using the pre-incorporation method. Physicochemical properties of the as-synthesized materials were characterized by means of various techniques, and their catalytic activities for CO, ethyl acetate, and toluene oxidation were evaluated. Among all of the samples, performed the best, with the reaction temperature required to achieve 90% conversion( T 90%) being 160 ℃ for CO oxidation, 210 ℃ for ethyl acetate oxidation, and 285 ℃ for toluene oxidation. Such a good catalytic performance of 5Fe/OMS-2 was associated with its high(Mn^(3+) + Mn^(2+)) content and adsorbed oxygen species concentration, and good lowtemperature reducibility and lattice oxygen mobility as well as strong interaction between Fe and OMS-2. In addition, catalytic mechanisms of the oxidation of three pollutants over the 5Fe/OMS-2 catalyst were also studied. It was found that CO, ethyl acetate or toluene was first adsorbed, then the related intermediates were formed, and finally the formed intermediates were completely converted into CO_(2) and H_(2)O.展开更多
Catalytic oxidation of toluene over noble metal catalysts is a representative reaction for elimination of volatile organic compounds(VOCs).However,to fully understand the activation of molecular oxygen and the role of...Catalytic oxidation of toluene over noble metal catalysts is a representative reaction for elimination of volatile organic compounds(VOCs).However,to fully understand the activation of molecular oxygen and the role of active oxygen species generated in this reaction is still a challenging target.Herein,MgO nanosheets and single-atom Pt loaded MgO(Pt SA/MgO)nanosheets were synthesized and used as catalysts in toluene oxidation.The activation process of molecular oxygen and oxidation performance on the two catalysts were contrastively investigated.The Pt SA/MgO exhibited significantly enhanced catalytic activity compared to MgO.The oxygen vacancies can be easily generated on the Pt SA/MgO surface,which facilitate the activation of molecular oxygen and the formation of active oxygen species.Based on the experimental data and theoretical calculations,an active oxygen species promoted oxidation mechanism for toluene was proposed.In the presence of H2O,the molecular oxygen is more favorable to be dissociated to generate•OH on the oxygen vacancies of the Pt SA/MgO surface,which is the dominant active oxygen species.We anticipate that this work may shed light on further investigation of t10.1007/s12274-020-2765-1he oxidation mechanism of toluene and other VOCs over noble metal catalysts.展开更多
Secondary organic aerosol （SOA） formed from Cl-initiated oxidation of toluene was investigated in a home-made smog chamber. The size distribution and chemical composition of SOA particles were measured using aerodyn...Secondary organic aerosol （SOA） formed from Cl-initiated oxidation of toluene was investigated in a home-made smog chamber. The size distribution and chemical composition of SOA particles were measured using aerodynamic particle sizer spectrometer and the aerosol laser time-of-flight mass spectrometer （ALTOFMS）, respectively. According to a large number of single aerosol diameter and mass spectra, the size distribution and chemical composition of SOA were obtained statistically. Experimental results showed that SOA particles created by Cl-initiated oxidation of toluene is predominantly in the form of fine particles, which have diameters less than 2.5 μm （i.e., PM2.5）, and glyoxal, benzaldehyde, benzyl alcohol, benzoquinone, benzoic acid, benzyl hydroperoxide and benzyl methyl nitrate are the major products components in the SOA. The possible reaction mechanisms leading to these products are also proposed.展开更多
基金The National Natural Science Foundation of China(No.21276050)the Scientific Research Foundation of Graduate School of Southeast University(No.YBJJ1341)
文摘γ-MnO2 nanorobs and Au/γ-MnO2 catalysts were synthesized and characterized by the X-ray powder diffraction XRD the scanning electron microscope SEM and transmission electron microscope TEM . The characterizations show that Au particles are well dispersed on the surface of γ-MnO2 nanorobs with a particle size of about 10 nm.The catalytic performance is evaluated in solvent-free toluene oxidation with oxygen. The influences of several process parameters such as reaction time reaction temperature initial oxygen pressure and catalyst amounts on the catalytic performance are studied.Catalytic results reveal that Au/γ-MnO2 catalyst has a unique selectivity to benzaldehyde and all these factors greatly influence the conversion of toluene and selectivity of bezaldehyde benzoic acid and benzyl benzoate.However these factors have slight influence on the selectivity of benzyl alcohol.
基金supported by the National Natural Science Foundation of China(21377016,21577014)Program for Changjiang Scholars and Innovative Research Team in University(IRT_13R05)~~
文摘The catalytic oxidation of toluene over Ag/SBA‐15synthesized under different pretreatment conditions,including O2at500°C(denoted O500),H2at500°C(H500),and O2at500°C followed by H2at300°C(O500‐H300)was studied.The pretreated samples were investigated by N2physisorption,X‐ray diffraction,and ultraviolet‐visible diffuse reflectance.The pretreatment atmosphere greatly influences the status of the Ag and O species,which in turn significantly impacts the adsorption and catalytic removal of toluene.Ag2O and amorphous Ag particles,as well as a large amount of subsurface oxygen species,are formed on O500,and the subsurface oxygen enhances the interaction between Ag species and toluene,so O500shows good activity at higher temperature.However,its activity at lower temperature is not as high as expected,with a reduced presence of Ag2O and lower adsorption capacity for toluene.H2pretreatment at500°C is conducive to the formation of large Ag particles and yields the largest adsorption capacity for toluene,so H500exhibits the best activity at lower temperatures;however,because of poor interaction between Ag and toluene,its activity at higher temperature is modest.The O500‐H300sample exhibits excellent catalytic activity during the whole reaction process,which can be attributed to the small and highly dispersed Ag nanoparticles as well as the existence of subsurface oxygen.
文摘Herein,a bottom-down design is presented to successfully fabricate ZIF-derived Co3O4,grown in situ on a one-dimensional(1D)α-MnO2 material,denoted as α-MnO2@Co3O4.The synergistic effect derived from the coupled interface constructed betweenα-MnO2 and Co3O4 is responsible for the enhanced catalytic activity.The resultantα-MnO2@Co3O4 catalyst exhibits excellent catalytic activity at a T90%(temperature required to achieve a toluene conversion of 90%)of approximately 229℃,which is 47 and 28℃ lower than those of the pureα-MnO2 nanowire and Co3O4-b obtained via pyrolysis of ZIF-67,respectively.This activity is attributed to the increase in the number of surface-adsorbed oxygen species,which accelerate the oxygen mobility and enhance the redox pairs of Mn^4+/Mn^3+ and Co^2+/Co^3+.Moreover,the result of in situ diffuse reflectance infrared Fourier transform spectroscopy suggests that the gaseous oxygen could be more easily activated to adsorbed oxygen species on the surface of α-MnO2@Co3O4 than on that of α-MnO2.The catalytic reaction route of toluene oxidation over theα-MnO2@Co3O4 catalyst is as follows:toluene→benzoate species→alkanes containing oxygen functional group→CO2 and H2O.In addition,the α-MnO2@Co3O4 catalyst shows excellent stability and good water resistance for toluene oxidation.Furthermore,the preparation method can be extended to other 1D MnO2 materials.A new strategy for the development of high-performance catalysts of practical significance is provided.
基金Project supported by the Sichuan Provincial Science and Technology Agency Support Projects(2020YFG0066)Young Talent Team Science and Technology Innovation Project of Sichuan Province(2020JDTD0005)。
文摘Co-based catalysts are the most promising catalysts in catalytic oxidation of volatile organic compounds(VOCs).Precious metal doping is adopted to improve the catalytic activity of toluene on Co_(3)O_(4) catalysts,but greatly increases its cost along with it.It is found that doping a small amount of rare earth(Ce,Pr,Sm and Nd)can dramatically promote the catalytic activity of Co_(3)O_(4).Especially,the Nd-doped Co_(3)O_(4) catalyst exhibits excellent catalytic activity with a toluene removal rate of 90% at 162.1℃,which is even better than that of Pt-doped Co_(3)O_(4).Compared with other rare earth metal doping,the Nd doping leads to a higher ratio of Co^(3+)/Co^(2+) and has more oxygen vacancies.The in situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)experiments show that the lattice oxygen of Nd-Co sample can be utilized at a quite low temperature,while that of pure Co_(3)O_(4) cannot engage in oxidation reaction when the temperature is below 200℃,which visually demonstrates the main reason for the improved catalytic performance of Nd-Co catalyst.
基金Project supported by the Fundamental Research Funds for the Cornell University(30919011220)the Key Project of Jiangsu Province Programs for Research and Development(BE2019115)+1 种基金Top-notch Academic Programs Project of Jiangsu Higher Education InstitutionsChina-Finland Industrial R&D Program(BZ2018015)。
文摘In this study,K_(x)-Mn-Ce catalysts prepared by sol-gel method were investigated for toluene oxidation.Compared with Mn-Ce,the catalytic performance of K_(x)-Mn-Ce was further improved.X-ray diffraction(XRD),high resolution transmission electron microscopy(HRTEM)and Raman analyses demonstrate that K ions enter the lattice of CeO_(2) and disperse uniformly.The results of X-ray photoelectron spectroscopy(XPS),H_(2)-temperature programmed reduction(H_(2)-TPR).and O_(2)-temperature programmed desorption(O_(2)-TPD)analyses indicate that there is a strong interaction between K,Mn and Ce;the charge co mpensation effect would be induced when K ions enter the lattice of CeO_(2),which leads to more oxygen vacancies due to the generation of more Ce^(3+).Toluene-TPD shows that K-doping enhances the activation ability of toluene.Among all catalysts,K0.1-Mn-Ce shows the highest concentration of Mn^(4+),Ce^(3+),Osur,and redox ability,resulting in higher low-temperature catalytic activity.Additionally,the results of stability and water resistance also prove that K0.1-Mn-Ce catalyst possesses excellent stability and water resistance.
基金supported by the Fundamental Research Funds for the Central Universities (No. 2021ZY79)Beijing Municipal Education Commission through the Innovative Transdisciplinary Program "Ecological Restoration Engineering” (No. GJJXK210102)+2 种基金National Natural Science Foundation of China (Nos. 42075169, U1810209)National Key R&D Program of China (No. 2021YFE0110800)Chinese-Serbian collaboration project (No. 451-03-1205/2021-09)。
文摘A series of monolithic MnO_(2)/iron mesh (IM) catalysts for oxidation of toluene were successfully prepared by using in situ hydrothermal growth.MnO_(2)can grow firmly on the IM substrates surface with a shedding rate of only 0.14%.Due to the highest O_(ads) and high-valent Mn^(4+) and Fe^(3+) elements,the temperature at 50% and 90% toluene conversion (T_(50%) and T_(90%)) was 252 and 265℃,respectively for the best performance catalyst (hydrothermal temperature of 80℃,hydrothermal time of 12 h,and precursor manganese ion concentration of 0.03 mol/L).The catalysts also presented good water resistance and cycle performance.In-situ DRIFTS results suggesting that toluene was first rapid transformed into the reaction intermediate species (benzoate species) and then converted to CO_(2)and H_(2)O.Therefore,this work provides a new direction for the research and application of IM-based monolithic catalysts.
基金supported by the National Natural Science Foundation of China (Nos. 21277008 and 20777005)National Key Research and Development Program of China (No. 2017YFC0209905)。
文摘The cryptomelane-type manganese oxide (OMS-2)-supported Co (x Co/OMS-2;x=5,10,and15 wt.%) catalysts were prepared via a pre-incorporation route.The as-prepared materials were used as catalysts for catalytic oxidation of toluene (2000 ppmV).Physical and chemical properties of the catalysts were measured using the X-ray diffraction (XRD),Fourier transform infrared spectroscopic (FT-IR),scanning electron microscopic (SEM),X-ray photoelectron spectroscopy (XPS),and hydrogen temperature-programmed reduction (H_(2)-TPR)techniques.Among all of the catalysts,10Co/OMS-2 performed the best,with the T90%,specific reaction rate at 245℃,and turnover frequency at 245℃ (TOFCo) being 245℃,1.23×10^(-3)moltoluene/(gcat·sec),and 11.58×10^(-3)sec-1for toluene oxidation at a space velocity of 60,000mL/(g·hr),respectively.The excellent catalytic performance of 10Co/OMS-2 were due to more oxygen vacancies,enhanced redox ability and oxygen mobility,and strong synergistic effect between Co species and OMS-2 support.Moreover,in the presence of poisoning gases CO_(2),SO_(2)or NH_(3),the activity of 10Co/OMS-2 decreased for the carbonate,sulfate and ammonia species covered the active sites and oxygen vacancies,respectively.After the activation treatment,the catalytic activity was partly recovered.The good low-temperature reducibility of 10Co/OMS-2 could also facilitate the redox process accompanied by the consecutive electron transfer between the adsorbed O_(2)and the cobalt or manganese ions.In the oxidation process of toluene,the benzoic and aldehydic intermediates werefirst generated,which were further oxidized to the benzoate intermediate that were eventually converted into H_(2)O and CO_(2).
基金support from National Key Research and Development Program of China(No.2019YFC1903903)the National Natural Science Foundation of China(No.21876019)+1 种基金Fundamental Research Funds for the Central Universities(No.DUT20RC(4)003)Natural Science Foundation of Liaoning Province(No.2020-BS-056).
文摘La_(1-x)CoO_(3-δ)catalysts with different non-stoichiometry of lanthanum ions were synthesized by using the sol-gel method,and their catalytic performance in toluene combustion was investigated.The results showed that the catalytic activity and stability of A-site nonstoichiometric La_(1-x)CoO_(3-δ)were improved to a certain extent compared with pure LaCoO_(3)perovskite.Among them,the La_(0.9)CoO_(3-δ)catalyst gave the best catalytic performance for toluene oxidation.It achieved 90%toluene conversion at 205℃under the conditions of a WHSV(weight hourly space velocity)of 22,500 mL/(g·hr)and a 500 ppmV-toluene concentration.Various characterization techniques were used to investigate the relationship between the structure of these catalysts and their catalytic performance.It was found that the non-stoichiometric modification of the lanthanum ion at position A in LaCoO_(3)changed the surface element state of the catalyst and increased the oxygen vacancy content,thus,combined with improved reducibility,improving toluene degradation on the catalyst.
基金supported by the National Natural Science Foundation of China(21322202,21472187)the National Basic Research Program of China(2010CB833300)~~
文摘The selective oxidation of toluene and its derivatives is extremely important in the chemical industry.The use of photocatalysis in organic synthesis has attracted considerable attention among synthetic chemists because of its ＂green＂ environmental characteristics.In this study,nanoscale Bi_2WO_6with a flower-like morphology was found to be a highly efficient photocatalyst in the catalytic oxidation of toluene and its derivatives using O_2 as the oxidant.The loading of Pd nanoparticles as a cocatalyst onto the flower-like Bi_2WO_6 was found to produce a significant enhancement in the catalytic activity.Mechanistic investigation showed that the superior performance of Pd/Bi_2WO_6 could be attributed to the improvement of both the reductive and oxidative abilities of Bi_2WO_6 by the loading of the cocatalyst.
基金Project supported by the Natural Science Foundation for the Higher Education Institutions of Anhui Province of China(KJ2020A0236,KJ2018A0638,KJ2019A0079)。
文摘The plane exposure of support vitally affects the catalytic performance of the catalyst.In this work,CeO_(2)nanorods((110)plane exposure),nano-octahedrons((111)plane exposure)and nano-cubes((100)plane exposure)were prepared as the supports of Pt/CeO_(2)samples to investigate the effect of CeO_(2)plane exposure on total toluene oxidation.Characterizations reveal that the(110)plane of CeO_(2)is more helpful to the dispersion of Pt species,followed by(111)face.The improved dispersion of Pt species can enhance the metal-supports interaction,which promotes the electron transfer of CeO_(2)carrier to Pt nanoparticles and the adsorption-activation of O_(2),thereby facilitating the total oxidation of toluene via the Langmuir-Hinshelwood(L-H)mechanism.Therefore,Pt/CeO_(2)-r(nanorods)sample expresses excellent catalytic performance of toluene oxidation.Finally,the procedure of toluene total oxidation was studied by in-situ diffuse reflectance infrared Fourier transform(DRIFT)spectroscopy.We expect that this work can contribute to the development of an effective sample for the decomposition of volatile organic compounds(VOCs).
基金supported by the National Natural Science Foundation of China(91434101,91745108)the Ministry of Science and Technology of the People’s Republic of China(2017YFB0702900)~~
文摘A series of hexadecylphosphate acid(HDPA) terminated mixed-oxide nanoparticles have been investigated to catalyze the oxidation of toluene exclusive to benzaldehyde under mild conditions in an emulsion of toluene/water with the catalysts as stabilizers. With the HDPA-Fe2 O3/Al2 O3 as the basic catalyst, a series of transition metals, such as Mn, Co, Ni, Cu, Cr, Mo, V, and Ti, was respectively doped to the basic catalyst to modify the performance of the catalytic system, in expectation of influencing the mobility of the lattice oxygen species in the oxide catalysts. Under normally working conditions of the catalytic system, the nanoparticles of catalysts located themselves at the interface between the oil and water phases, constituting the Pickering emulsion. Both the doped iron oxide and its surface adsorbed hexadecylphosphate molecules were essential to the catalytic system for excellent performances with high toluene conversions as well as the exclusive selectivity to benzaldehyde. Under optimal conditions, ~83% of toluene conversion and >99% selectivity to benzaldehyde were obtained, using molecular oxygen as oxidant and HDPA-(Fe2 O3-Ni O)/Al2 O3 as the catalyst. This process is green and low cost to produce high quality benzaldehyde from O2 oxidation of toluene.
基金financially supported by the China Postdoctoral Science Foundation(No.2018M643090)the National Natural Science Foundation of China(No.52000077)+3 种基金the National Key Research and Development Project of Research(No.2017YFC0212805)the National Natural Science Foundation of China(No.51878292)the Natural Science Foundation of Guangdong Province,China(No.2015B020236002)the China Postdoctoral Science Foundation(No.2020M682715).
文摘A facile hydrothermal method was applied to gain stably and highly efficient CuO-CeO_(2)(denoted as Cu1Ce2)catalyst for toluene oxidation.The changes of surface and inter properties on Cu1Ce2 were investigated comparing with pure CeO_(2)and pure CuO.The formation of Cu-Ce interface promotes the electron transfer between Cu and Ce through Cu^(2+)+Ce^(3+)↔Cu^(+)+Ce^(4+)and leads to high redox properties and mobility of oxygen species.Thus,the Cu1Ce2 catalyst makes up the shortcoming of CeO_(2)and CuO and achieved high catalytic performance with T_(50)=234°C and T_(99)=250°C(the temperature at which 50%and 90%C_(7)H_(8)conversion is obtained,respectively)for toluene oxidation.Different reaction steps and intermediates for toluene oxidation over Cu1Ce2,CeO_(2)and CuO were detected by in situ DRIFTS,the fast benzyl species conversion and preferential transformation of benzoates into carbonates through C=C breaking over Cu1Ce2 should accelerate the reaction.
基金supported by the Fundamental Research Funds for the Central Universities (No. 2019JQ03015)the National Natural Science Foundation of China (No. U1810209)+1 种基金the International Science and Technology Cooperation Project of Bingtuan (No. 2018BC002)the Beijing Municipal Educa-tion Commission for their financial support through Innova-tive Transdisciplinary Program “Ecological Restoration Engi-neering”。
文摘In this paper, KMnO4 was used to pre-treat Co3 Fe-layered double hydroxides(LDH) precursor to prepare MnO2 decorated Co3Fe1Ox catalyst. The toluene oxidation performance of the catalyst was investigated systematically. The optimized 0.1 Mn CF-LDO catalyst exhibited the best catalytic performance, and the temperatures of 50% and 90% toluene conversion( T50 and T90) were 218 and 243 ℃, respectively. The apparent activation energy( Ea) was 31.6 k J/mol. The characterization results showed that the pre-redox reaction by KMnO4 could increase the specific surface area, Co^3+ species amount and oxygen defect concentration of the catalyst, which are the main reason of the improved toluene catalytic activity. Besides, this method was also applied to enhance toluene oxidation of iron mesh based monolithic catalyst. The 0.1 Mn CF-LDO/Iron mesh(IM) catalyst showed a 90% toluene conversion at around 316 ℃ which was much lower than that of without MnO2 addition(359 ℃). In addition, the water resistant of all the catalysts was studied as well, all the samples showed relatively good water resistance. The toluene conversion still remained to be over > 80% even in the presence of 10 vol.% water vapor.
基金supported by the National Research Council of Science and Technology(NST)through Degree and Research Center(DRC)Program(2015)
文摘We deposited NiO via atomic layer deposition on mesoporous SiO2 particles with diameters of several hundred micrometers and a mean mesopore size of -14 nm.NiO was deposited within the shell region of mesoporous SiO2 particles with a shell thickness of -11 mm.We annealed the as-prepared NiO/SiO2 at 450 and 600℃,respectively.These two samples were used as catalysts for the uptake of toluene molecules and their oxidative conversion to CO2.The sample annealed at450℃ was generally more reactive in toluene uptake and its subsequent conversion to CO2.When the NiO/SiO2 annealed at 450℃ was exposed to toluene vapor at 160℃ and then heated to 450℃,CO2 was emitted with almost no toluene desorption.We suggest that our catalysts can be used as building blocks for odor removal devices that operate below 200℃.These catalysts can be regularly regenerated at -450℃.
基金Supported by the National Natural Science Foundation of China(Nos.20502017and20072024)the Teaching and ResearchAward Program for Outstanding Young Teachers in Higher Education Institutions of Ministry of Education,Chinathe ScienceFoundation for Young Teachers of Sichuan University.
文摘The selective catalytic oxidation of toluene with hydrogen peroxide over V-Mo-based catalysts under mild conditions was studied.The promotion effect of Mo on the catalysts was studied with V/Al2O3 and Mo/Al2O3 as reference samples.The catalysts were characterized by XRD,TPR,and XPS techniques.The results show that the addition of Mo to V/Al2O3 may change the distribution of V species on Al2O3 surface.Over V-Mo/Al2O3 catalyst,highly dispersed amorphous V species facilitates benzaldehyde formation,and crystalline V2O5 species increases the conversion of toluene but decreases the selectivity to benzaldehyde,while AlVMoO7 species favors both the conversion of toluene and the formation of cresols.The yield of benzaldehyde depends remarkably on the surface O/Al and Mo/V atomic ratios,and gets to a maximum value of 13.2% with a selectivity of 79.5% at an O/Al atomic ratio of 3.0 and Mo/V atomic ratio of 0.7.
文摘Mesoporous carbon-supported cobalt （Co-MC） catalysts are widely applied as electrode materials for bat- teries. Conversely, the development of Co-MC as bifunctional catalysts for application in organic catalytic reactions and degradation of water contaminants is slower. Herein, the catalyst displayed high activity in the selective oxidation of toluene to benzaldehyde under mild conditions, attaining a high selectivity of 92.3%. Factors influencing the catalytic reaction performance were also investigated. Additionally, Co-MC displayed remarkable catalytic activity in degrading dyes relative to the pure metal counterpart. Moreover, the catalyst exhibited excellent reusability, as determined by the cyclic catalytic experiments. The paper demonstrates the potential of Co-MC as a bifunctional catalyst for both toluene selective oxidation and water contaminant degradation.
基金financially supported by the National Natural Science Foundation of China(No.21876019 and 21806017)National Key Research and Development Program of China(No.2019YFC1903903)+1 种基金Fundamental Research Funds for the Central Universities(No.DUT19LAB10)Dalian Science and Technology Innovation Fund(No.2019J12SN74).
文摘Herein,Na^(+)and Ca^(2+)are introduced to MnO_(2)through cation-exchange method.The presence of Na^(+)and Ca^(2+)significantly enhance the catalytic activity of MnO_(2)in toluene oxidation.Among them,the Ca-MnO_(2)catalyst exhibits the best catalytic activity(T_(50)=194℃,T_(90)=215℃,E_a=57.2 k J/mol,reaction rate 8.40×10^(-10)mol/(sec·m^(2))at 210℃.T_(50)and T_(90):the temperature of 50%and 90%toluene conversion;E a:apparent activation energy)and possess high tolerance against 2.0 vol.%water vapor.Results reveal that the increased acidic sites of the MnO_(2)sample can enhance the adsorption of gaseous toluene,and the mobility of oxygen species and the content of reactive oxygen species in the catalyst are significantly improved due to the formed oxygen vacancy.Thus these two factors result in excellent catalytic performance for toluene oxidation combining with the weak CO_(2)adsorption ability.
基金supported by the National Natural Science Foundation of China (Nos. 21277008 and 20777005)National Key Research and Development Program of China (No. 2017YFC0209905)Natural Science Foundation of Beijing (No. 8082008 )。
文摘The octahedral molecular sieve(OMS-2)-supported Fe( xFe/OMS-2: x = 1, 3, 5, and 10) catalysts were prepared using the pre-incorporation method. Physicochemical properties of the as-synthesized materials were characterized by means of various techniques, and their catalytic activities for CO, ethyl acetate, and toluene oxidation were evaluated. Among all of the samples, performed the best, with the reaction temperature required to achieve 90% conversion( T 90%) being 160 ℃ for CO oxidation, 210 ℃ for ethyl acetate oxidation, and 285 ℃ for toluene oxidation. Such a good catalytic performance of 5Fe/OMS-2 was associated with its high(Mn^(3+) + Mn^(2+)) content and adsorbed oxygen species concentration, and good lowtemperature reducibility and lattice oxygen mobility as well as strong interaction between Fe and OMS-2. In addition, catalytic mechanisms of the oxidation of three pollutants over the 5Fe/OMS-2 catalyst were also studied. It was found that CO, ethyl acetate or toluene was first adsorbed, then the related intermediates were formed, and finally the formed intermediates were completely converted into CO_(2) and H_(2)O.
基金This work was financially supported by National Natural Science Foundation of China (Nos. 51808037, 21601136 and 21876010)the Science & Technology Development Fund of Tianjin Education Commission for Higher Education (No. 2018KJ126)the Fundamental Research Funds for the Central Universities (No. FRF-TP-16-060A1).
文摘Catalytic oxidation of toluene over noble metal catalysts is a representative reaction for elimination of volatile organic compounds(VOCs).However,to fully understand the activation of molecular oxygen and the role of active oxygen species generated in this reaction is still a challenging target.Herein,MgO nanosheets and single-atom Pt loaded MgO(Pt SA/MgO)nanosheets were synthesized and used as catalysts in toluene oxidation.The activation process of molecular oxygen and oxidation performance on the two catalysts were contrastively investigated.The Pt SA/MgO exhibited significantly enhanced catalytic activity compared to MgO.The oxygen vacancies can be easily generated on the Pt SA/MgO surface,which facilitate the activation of molecular oxygen and the formation of active oxygen species.Based on the experimental data and theoretical calculations,an active oxygen species promoted oxidation mechanism for toluene was proposed.In the presence of H2O,the molecular oxygen is more favorable to be dissociated to generate•OH on the oxygen vacancies of the Pt SA/MgO surface,which is the dominant active oxygen species.We anticipate that this work may shed light on further investigation of t10.1007/s12274-020-2765-1he oxidation mechanism of toluene and other VOCs over noble metal catalysts.
基金supported by the Open Research Fund of Key Laboratory of Atmospheric Composition and Optical Radiation, Chinese Academy of Sciences (No. JJ-10-04)the National Natural Science Foundation of China (No.40975080, 10979061)class A technology fund of Department of Education of Fujian Province (No. JA11290)
文摘Secondary organic aerosol （SOA） formed from Cl-initiated oxidation of toluene was investigated in a home-made smog chamber. The size distribution and chemical composition of SOA particles were measured using aerodynamic particle sizer spectrometer and the aerosol laser time-of-flight mass spectrometer （ALTOFMS）, respectively. According to a large number of single aerosol diameter and mass spectra, the size distribution and chemical composition of SOA were obtained statistically. Experimental results showed that SOA particles created by Cl-initiated oxidation of toluene is predominantly in the form of fine particles, which have diameters less than 2.5 μm （i.e., PM2.5）, and glyoxal, benzaldehyde, benzyl alcohol, benzoquinone, benzoic acid, benzyl hydroperoxide and benzyl methyl nitrate are the major products components in the SOA. The possible reaction mechanisms leading to these products are also proposed.
