The doping of functionalized graphene oxide(GO)in the membranes becomes a promising method for improving the performance of high-temperature proton exchange membrane fuel cells(HT-PEMFC).Phosphonated graphene oxide(PG...The doping of functionalized graphene oxide(GO)in the membranes becomes a promising method for improving the performance of high-temperature proton exchange membrane fuel cells(HT-PEMFC).Phosphonated graphene oxide(PGO)with a P/O ratio of 8.5%was quickly synthesised by one-step electrochemical exfoliation based on a three-dimensiaonal(3D)printed reactor and natural graphite flakes.Compared with the GO prepared by the two-step electrochemical exfoliation method,the PGO synthesized by the one-step electrochemical exfoliation can better improve the performance of the membrane-electrode-assembly(MEA)based on the polybenzimidazole(PBI)membrane in the HTPEMFC.The doping of 1.5 wt%GO synthesised by electrochemical exfoliation with the 2-step method or reactor method in PBI increased the peak power density by 17.4%or 35.4%compared to MEA based on pure PBI membrane at 150℃,respectively.In addition,the doping of PGO in PBI improves its durability under accelerated stress test(AST).展开更多
Electrochemical production of hydrogen from water requires the development ofelectrocatalysts that are active,stable,and low-cost for water splitting.To address these challenges,researchers are increasingly exploring ...Electrochemical production of hydrogen from water requires the development ofelectrocatalysts that are active,stable,and low-cost for water splitting.To address these challenges,researchers are increasingly exploring binder-free electrocatalytic integratedelectrodes (IEs) as an alternative to conventional powder-based electrode preparation methods,for the former is highly desirable to improve the catalytic activity and long-term stability for large-scale applications of electrocatalysts.Herein,we demonstrate a laser-inducedhydrothermal reaction (LIHR) technique to grow NiMoO4nanosheets on nickel foam,which is then calcined under H2/Ar mixed gases to prepare the IE IE-NiMo-LR.This electrode exhibits superior hydrogen evolution reaction performance,requiring overpotentials of 59,116 and143 mV to achieve current densities of 100,500 and 1000 mA·cm-2.During the 350 h chronopotentiometry test at current densities of 100 and 500 m A·cm-2,the overpotentialremains essentially unchanged.In addition,NiFe-layered double hydroxide grown on Ni foam is also fabricated with the same LIHR method and coupled with IE-NiMo-IR to achieve water splitting.This combination exhibits excellent durability under industrial current density.The energy consumption and production efficiency of the LIHR method are systematicallycompared with the conventional hydrothermal method.The LIHR method significantly improves the production rate by over 19 times,while consuming only 27.78%of the total energy required by conventional hydrothermal methods to achieve the same production.展开更多
The goal of this study was to determine whether mutation of the Mn-binding site of wild-type recombinant Phlebia radiata manganese peroxidase 3 affected the pH-dependence kinetic parameters. pH range investigated was ...The goal of this study was to determine whether mutation of the Mn-binding site of wild-type recombinant Phlebia radiata manganese peroxidase 3 affected the pH-dependence kinetic parameters. pH range investigated was 2.5 – 12.0. The catalytic efficiency of the mutant enzymes at high and low pH in comparison to the wild-type was investigated using standard rPr-MnP3 protocol. Wild-type recombinant Phlebia radiata MnP3 enzyme showed optimal activity with Mn (II) as substrate at pH 5.0 and remained moderately active (approximately 40%) in the pH range of 6.0 - 9.0. The rPr-MnP3 mutants’ maximum activity ranged between 5.5 and 8.0. Wild-type and mutants rPr-MnP3 enzymes exhibited a similar pH profile with optimum pH of 3.0 for ABTS oxidation. Mutation has severely decreased the catalytic efficiency for Mn (II) oxidation at pH 5.0. The rPr-MnP3 enzymes showed enhanced affinity for Mn (II) at alkaline pH and a more alkaline range for catalysis than ever reported for any Manganese Peroxidase. This study reveals that at higher pH, rPr-MnP3 can function with alternative ligands in the Mn (II) site and does not have an absolutely obligate requirement for an all carboxylate ligand set. These results further strongly confirm that Mn<sup>2+</sup> binding site is the only productive catalytic site for Mn (II) oxidation.展开更多
This investigation is aimed at understanding the specific role of pH and calcium ions on the activity and stability of wild-type recombinant Phlebia radiata manganese peroxidase 3 (rPr-MnP3). The pH-dependent cycle of...This investigation is aimed at understanding the specific role of pH and calcium ions on the activity and stability of wild-type recombinant Phlebia radiata manganese peroxidase 3 (rPr-MnP3). The pH-dependent cycle of reactions for rPr-MnP3 was evaluated by investigating time-dependent changes in the activity and electronic absorption spectrum of rPr-MnP3.The rPr-MnP3 had maximum efficacy (kcat/Km) for Mn (II) oxidation at pH 5.0 and 3.0 for oxidation of ABTS. Raising the pH of a solution of resting rPr-MnP3 from pH 6.7 (form XH) to pH 8.6 (form X<sup>−</sup>), a rapid alkaline transition occurs. Leaving the X<sup>−</sup> form of the enzyme at pH 8.6, it slowly becomes converted to a third form of the enzyme Y<sup>−</sup>, which returned to the original XH form of the enzyme at pH 6.7. Recovery of form XH from form Y<sup>−</sup> occurred through an intermediate Z form. The pH inactivation of rPr-MnP3 followed first-order kinetics. The rate of formation of XH from Z is pH-dependent and biphasic in nature, with measured rate constants (k) = 0.25 min<sup>−1</sup>, and half-life (T<sub>1/2</sub>) = 2.8 min. The pH-dependent properties observed may be indicative of a greater degree of conformational flexibility at rPr-MnP3 active site due to disruption of the haem-linked hydrogen-bonding network in the distal haem pocket. Calcium ions were observed to significantly stabilised the enzyme’s spectral features and reduce the loss of activity during the alkaline pH transition. Calcium ions enhance the recovery of the initial activity but cannot prevent the final time-dependent irreversible denaturation and aggregation.展开更多
Post-consumer polymeric wastes in form of low-density polyethylene (LDPE) can now be considered suitable as a precursor for the synthesis of low-cost activated carbon (AC). This study produced AC from LDPE using sulph...Post-consumer polymeric wastes in form of low-density polyethylene (LDPE) can now be considered suitable as a precursor for the synthesis of low-cost activated carbon (AC). This study produced AC from LDPE using sulphuric acid (H<sub>2</sub>SO<sub>4</sub>) and potassium hydroxide (KOH) as the activating agent. The reaction conditions for pyrolysis were varied in the range of 0.50 - 2.00 M, 400<span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#ffffff;"="">°</span>C - 500<span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#ffffff;"="">°</span>C, and 45 - 60 minutes. Physico-chemical investigations reveal that AC yield is significantly dependent on both carbonization temperatures and time. The obtained optimum values of 446.50<span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#ffffff;"="">°</span>C and 51.09 mins gave a yield of 24% for the base-activated carbon. The high iodine numbers obtained strongly indicate the presence of large surface area and pore volumes is further confirmed using the Scanning Electron Microscopy (SEM) analysis which reveals the presence of pores on the external surface of the carbons. Fourier Transform Infrared Technique (FTIR) analysis further shows that the synthesized compounds are purely carbon with rich oxy-gen-surface complexes on the surface which is as a result of the introduction of the chemical oxidizing agents. The produced carbons were found to have high adsorption affinity for selected inorganic ions which are: Mn<sup>7+</sup>, Co<sup>2+</sup>, and Cr<sup>6+</sup>. Adsorption isotherm results show the adsorption process to be favourable with the Langmuir isotherm parameter RL having values of <1, while the Freudlich adsorption model was found to perfectly fit the data at selected adsorbent dosages and adsorbate concentrations. The pseu-do-second-order model provides the best correlation for the kinetic analysis. The acid-activated carbon was found to have better adsorption capacities than the base-activated carbon.展开更多
The transverse relaxation time (T_(2)) cut-off value plays a crucial role in nuclear magnetic resonance for identifying movable and immovable boundaries, evaluating permeability, and determining fluid saturation in pe...The transverse relaxation time (T_(2)) cut-off value plays a crucial role in nuclear magnetic resonance for identifying movable and immovable boundaries, evaluating permeability, and determining fluid saturation in petrophysical characterization of petroleum reservoirs. This study focuses on the systematic analysis of T_(2) spectra and T_(2) cut-off values in low-permeability reservoir rocks. Analysis of 36 low-permeability cores revealed a wide distribution of T_(2) cut-off values, ranging from 7 to 50 ms. Additionally, the T_(2) spectra exhibited multimodal characteristics, predominantly displaying unimodal and bimodal morphologies, with a few trimodal morphologies, which are inherently influenced by different pore types. Fractal characteristics of pore structure in fully water-saturated cores were captured through the T_(2) spectra, which were calculated using generalized fractal and multifractal theories. To augment the limited dataset of 36 cores, the synthetic minority oversampling technique was employed. Models for evaluating the T_(2) cut-off value were separately developed based on the classified T_(2) spectra, considering the number of peaks, and utilizing generalized fractal dimensions at the weight <0 and the singular intensity range. The underlying mechanism is that the singular intensity and generalized fractal dimensions at the weight <0 can detect the T_(2) spectral shift. However, the T_(2) spectral shift has negligible effects on multifractal spectrum function difference and generalized fractal dimensions at the weight >0. The primary objective of this work is to gain insights into the relationship between the kurtosis of the T_(2) spectrum and pore types, as well as to predict the T_(2) cut-off value of low-permeability rocks using machine learning and data augmentation techniques.展开更多
Bioethanol produced via valorisation of renewable biomass is of great interest to many industries.The increased availability and decreased cost of bioethanol make it a promising platform molecule to produce a wide ran...Bioethanol produced via valorisation of renewable biomass is of great interest to many industries.The increased availability and decreased cost of bioethanol make it a promising platform molecule to produce a wide range of value-added chemicals and fuels via the catalytic conversions.This paper provides a comprehensive review of catalytic conversions of bioethanol to a variety of chemicals/fuels such as hydrogen,C_(2)-C_(4)olefins,gasoline and small oxygenates.Specifically,the focus was placed on the relationship between the catalyst property(such as pore structure,acidity,active metal sites,and catalyst supports)and the catalytic performance(including catalyst activity and stability),as well as the reaction mechanisms involved.Future research avenues on the catalyst design for improving catalytic valorisation of bioethanol are also discussed.展开更多
Hydrogen(H2)production from photocatalytic reforming of cellulose is a promising way for sustainable H2 to be generated.Herein,we report a systematic study of the photocatalytic reforming of cellulose over Pt/m-TiO2(i...Hydrogen(H2)production from photocatalytic reforming of cellulose is a promising way for sustainable H2 to be generated.Herein,we report a systematic study of the photocatalytic reforming of cellulose over Pt/m-TiO2(i.e.mixed TiO2,80%of anatase and 20%of rutile)catalysts in water.The optimum operation condition was established by studying the effect of Pt loading,catalyst concentration,cellulose concentration and reaction temperature on the gas production rate of H2(r(H2))and CO2(r(CO2)),suggesting an optimum operation condition at 40°C with 1.0 g·L^-1of cellulose and 0.75 g·L^-1of 0.16-Pt/m-TiO2 catalyst(with 0.16 wt%Pt loadting)to achieve a relatively sound photocatalytic performance with rH2=9.95μmol·h^-1.It is also shown that although the photoreforming of cellulose was operated at a relatively mild condition(i.e.with an UV-A lamp irradiation at40°C in the aqueous system),a low loading of Pt at^0.16 wt%on m-TiO2 could promote the H2 production effectively.Additionally,by comparing the reaction order expressed from both r(H2)(a1)and r(CO2)(a2)with respect to cellulose and water,the possible mechanism of H2 production was proposed.展开更多
Excess crude glycerol derived as a by-product from biodiesel industry prompts the need to valorise glycerol to value-added chemicals.In this context,catalytic steam reforming of glycerol(SRG) was proposed as a promisi...Excess crude glycerol derived as a by-product from biodiesel industry prompts the need to valorise glycerol to value-added chemicals.In this context,catalytic steam reforming of glycerol(SRG) was proposed as a promising and sustainable alternative for producing renewable hydrogen(H2).Herein,the development of nickel(Ni) supported on ceria-modified mesoporous γ-alumina(γ-Al2 O3) catalysts and their applications in catalytic SRG(at550-750℃ atmospheric pressure and weight hourly space velocity,WHSV,of 44,122 ml·g^-1·h^-1(STP)) is presented.Properties of the developed catalysts were characterised using many technique s.The findings show that ceria modification improved Ni dispersion on γ-Al2 O3 catalyst support with highly active small Ni particles,which led to a remarkable catalytic performance with the total glycerol conversion(ca.99%),glycerol conversion into gaseous products(ca.77%) and H2 yield(ca.62%).The formation rate for H2 production(14.4 ×10^(-5)mol·s^-1·g^-1, TOF(H2)=3412 s^-1) was significantly improved with the Ni@12 Ce-Al2 O3 catalyst,representing nearly a 2-fold increase compared with that of the conventional Ni@AI2 O3 catalyst.In addition,the developed catalyst also exhibited comparatively high stability(for 12 h) and coke resistance ability.展开更多
This special issue of the Chinese Journal of Chemical Engineering(CJCh E)concerns with the current progress in advanced energy technologies and materials related to chemical science and technology,especially the work ...This special issue of the Chinese Journal of Chemical Engineering(CJCh E)concerns with the current progress in advanced energy technologies and materials related to chemical science and technology,especially the work in the field of renewable energy,energy storage,clean and efficient utilization of energy,aligning well to the scope of this Journal.The world is moving towards a sustainable,clean and low-carbon future via‘Energy Transition',i.e..展开更多
Following the CSCST-25 Special Issue[1]we continued this issue based on the 26th CSCST-SCI annual conference(CSCST-SCI 26),which was held at the Society of Chemical Industry(SCI)headquarter,14/15 Belgrave Square,Londo...Following the CSCST-25 Special Issue[1]we continued this issue based on the 26th CSCST-SCI annual conference(CSCST-SCI 26),which was held at the Society of Chemical Industry(SCI)headquarter,14/15 Belgrave Square,London SW 1X 8PS on the 4th and 5th Septem ber 2019.The annual conference had 4 sessions with 20 oral and 14 poster presentations,which featured several plenary and keynote lectures by national and international em inent speakers.展开更多
High-temperature proton exchange membrane fuel cells(HT-PEMFCs)are pursued worldwide as efficient energy conversion devices.Great efforts have been made in the area of designing and developing phosphoric acid(PA)-base...High-temperature proton exchange membrane fuel cells(HT-PEMFCs)are pursued worldwide as efficient energy conversion devices.Great efforts have been made in the area of designing and developing phosphoric acid(PA)-based proton exchange membrane(PEM)of HT-PEMFCs.This review focuses on recent advances in the limitations of acid-based PEM(acid leaching,oxidative degradation,and mechanical degradation)and the approaches mitigating the membrane degradation.Preparing multilayer or polymers with continuous network,adding hygroscopic inorganic materials,and introducing PA doping sites or covalent interactions with PA can effectively reduce acid leaching.Membrane oxidative degradation can be alleviated by synthesizing crosslinked or branched polymers,and introducing antioxidative groups or highly oxidative stable materials.Crosslinking to get a compact structure,blending with stable polymers and inorganic materials,preparing polymer with high molecular weight,and fabricating the polymer with PA doping sites away from backbones,are recommended to improve the membrane mechanical strength.Also,by comparing the running hours and decay rate,three current approaches,1.crosslinking via thermally curing or polymeric crosslinker,2.incorporating hygroscopic inorganic materials,3.increasing membrane layers or introducing strong basic groups and electron-withdrawing groups,have been concluded to be promising approaches to improve the durability of HT-PEMFCs.The overall aim of this review is to explore the existing degradation challenges and opportunities to serve as a solid basis for the deployment in the fuel cell market.展开更多
C1 chemistrymainly involves the catalytic transformation of C1molecules(i.e.,CO,CO2,CH4 and CH3OH),which usually encounters thermodynamic and/or kinetic limitations.To address these limitations,non-thermal plasma(NTP)...C1 chemistrymainly involves the catalytic transformation of C1molecules(i.e.,CO,CO2,CH4 and CH3OH),which usually encounters thermodynamic and/or kinetic limitations.To address these limitations,non-thermal plasma(NTP)activated heterogeneous catalysis offers a number of advantages,such as relatively mild reaction conditions and energy efficiency,in comparison to the conventional thermal catalysis.This review presents the state-of-the-art for the application of NTP-catalysis towards C1 chemistry,including the CO2 hydrogenation,reforming of CH4 and CH3OH,and water-gas shift(WGS)reaction.In the hybrid NTP-catalyst system,the plasma-catalyst interactions aremultifaceted.Accordingly,this reviewalso includes a brief discussion on the fundamental research into themechanisms of NTP activated catalytic C1 chemistry,such as the advanced characterisation methods(e.g.,in situ diffuse reflectance infrared Fourier transform spectroscopy,DRIFTS),temperatureprogrammed plasma surface reaction(TPPSR),kinetic studies.Finally,prospects for the future research on the development of tailor-made catalysts for NTP-catalysis systems(which will enable the further understanding of its mechanism)and the translation of the hybrid technique to practical applications of catalytic C1 chemistry are discussed.展开更多
Silica nanosheets(SN)derived from natural vermiculite(Verm)were successfully incorporated into polyethersulfone-polyvinylpyrrolidone(PES-PVP)polymer to fabricate high-temperature proton exchange membranes(HT-PEMs).The...Silica nanosheets(SN)derived from natural vermiculite(Verm)were successfully incorporated into polyethersulfone-polyvinylpyrrolidone(PES-PVP)polymer to fabricate high-temperature proton exchange membranes(HT-PEMs).The content of SN filler was varied(0.1-0.75 wt%)to study its influence on proton conductivity,power density and durability.Benefiting from the hydroxyl groups of SN that enable the formation of additional proton-transferring pathways,the inorganic-organic membrane displayed enhanced proton conductivity of 48.2 mS/cm and power density of 495 mW/cm^(2) at 150℃ without humidification when the content of SN is 0.25 wt%.Furthermore,exfoliated SN(E-SN)and sulfonated SN(S-SN),which were fabricated by a liquid-phase exfoliation method and silane condensation,respectively,were embedded in PES-PVP polymer matrix by a simple blending method.Due to the significant contribution from sulfonic groups in S-SN,the membrane with 0.25 wt%S-SN reached the highest proton conductivity of51.5 mS/cm and peak power density of 546 mW/cm^(2) at150℃,48%higher than the pristine PES-PVP membranes.Compared to unaltered PES-PVP membrane,SN added hybrid composite membrane demonstrated excellent durability for the fuel cell at 150℃.Using a facile method to prepare 2D SN from natural clay minerals,the strategy of exfoliation and functionalization of SN can be potentially used in the production of HT-PEMs.展开更多
Nitrogen doping of the carbon is an important method to improve the performance and durability of catalysts for proton exchange membrane fuel cells by platinum–nitrogen and carbon–nitrogen bonds. This study shows th...Nitrogen doping of the carbon is an important method to improve the performance and durability of catalysts for proton exchange membrane fuel cells by platinum–nitrogen and carbon–nitrogen bonds. This study shows that p-phenyl groups and graphitic N acting bridges linking platinum and the graphene/carbon black(the ratio graphene/carbon black = 2/3) hybrid support materials achieved the average size of platinum nanoparticles with(4.88 ± 1.79) nm. It improved the performance of the lower-temperature hydrogen fuel cell up to 0.934 W cm^(-2) at 0.60 V, which is 1.55 times greater than that of commercial Pt/C. Doping also enhanced the interaction between Pt and the support materials, and the resistance to corrosion, thus improving the durability of the low-temperature hydrogen fuel cell with a much lower decay of 10 mV at 0.80 A cm^(-2) after 30 k cycles of an in-situ accelerated stress test of catalyst degradation than that of 92 mV in Pt/C, which achieves the target of Department of Energy(<30 mV). Meanwhile,Pt/Nr EGO_(2)-CB_(3) remains 78% of initial power density at 1.5 A cm^(-2) after 5 k cycles of in-situ accelerated stress test of carbon corrosion, which is more stable than the power density of commercial Pt/C, keeping only 54% after accelerated stress test.展开更多
Silicalite-1(S1)foam was functionalized by supporting manganese-cobalt(Mn-Co)mixed oxides to develop the structured hierarchical catalyst(Mn-Co@SlF)for catalytic combustion for the first time.The self-supporting S1 fo...Silicalite-1(S1)foam was functionalized by supporting manganese-cobalt(Mn-Co)mixed oxides to develop the structured hierarchical catalyst(Mn-Co@SlF)for catalytic combustion for the first time.The self-supporting S1 foam with hierarchical porosity was prepared via hydrothermal synthesis with polyurethane(PU)foam as the template.Subsequently,Mn-Co oxide nano sheets were uniformly grown on the surface of S1 foams under hydrothermal conditions to prepare the structured hierarchical catalyst with specific surface area of 354 m^2·g^-1,micropore volume of 0.141 cm^3·g^-1 and total pore volume of 0.217 cm3·g^-1,as well as a good capacity to adsorb toluene(1.7 mmol·g^-1 at p/p0=0.99).Comparative catalytic combustion of toluene of over developed structured catalyst Mn-Co@SlF was performed against the control catalysts of bulk Mn-Co@S1(i.e.,the crushed Mn-Co@SlF)and unsupported Mn-Co oxides(i.e.,Mn-Co).Mn-Co@SlF exhibited comparatively the best catalytic performance,that is,complete and stable toluene conversion at 2480 C over 65 h due to the synergy between Mn-Co oxides and S1 foam,which provided a large number of oxygen vacancies,high redox capacity.In addition,the hierarchical porous structure also improved the accessibility of active sites and facilitated the global mass transfer across the catalyst bed,being beneficial to the catalysis and catalyst longevity.展开更多
Body-scanning exploiting 3-D imaging has revolutionised diagnostics and treatment in medicine. Process engineers would like to be similarly able to image chemical process units in 3-D, but without the Lmulti-million p...Body-scanning exploiting 3-D imaging has revolutionised diagnostics and treatment in medicine. Process engineers would like to be similarly able to image chemical process units in 3-D, but without the Lmulti-million price tag. UMIST and Leeds University have together, through the Virtual Centre for Industrial Process Tomography （http：//www.vcipt.org）, pioneered several electrical process tomography techniques and used them in a variety of applications. Illustrations are presented to show how electrical resistance tomography （ERT） has been developed for typical stirred vessels widely encountered in batch process manufacturing. The technique is potentially fast and inexpensive and capable of imaging both dynamic and pseudo-stationary processes. Examples from UMIST＇s two-tonne vessel will be presented for miscible tracer mixing, as well as gas-liquid and solid-liquid mixing.展开更多
With the continuous growth of the world population,the demand for fresh water is ever increasing.Water desalination is a means of producing fresh water from saline water,and one of the proposed solutions in the scient...With the continuous growth of the world population,the demand for fresh water is ever increasing.Water desalination is a means of producing fresh water from saline water,and one of the proposed solutions in the scientific community for solving the current global freshwater shortage.Adsorption is foreseen as a promising technology for desalination due to its relatively low energy requirements,low environmental impact,low cost and high salt removal efficiency.More importantly,chemicals are not required in adsorption processes.Active carbons,zeolites,carbon nanostructures,graphene and coordination framework materials are amongst the most investigated adsorbents for adsorption desalination,which show different performances regarding adsorption rate,adsorption capacity,stability and recyclability.In this review,the latest adsorbent materials with their features are assessed(using metrics)and commented critically,and the current trend for their development is discussed.The adsorption mode is also reviewed,which can provide guidance for the design of adsorbents from the engineering application point of view.展开更多
基金financially supported by the UK Research Council EPSRC EP/009050/1。
文摘The doping of functionalized graphene oxide(GO)in the membranes becomes a promising method for improving the performance of high-temperature proton exchange membrane fuel cells(HT-PEMFC).Phosphonated graphene oxide(PGO)with a P/O ratio of 8.5%was quickly synthesised by one-step electrochemical exfoliation based on a three-dimensiaonal(3D)printed reactor and natural graphite flakes.Compared with the GO prepared by the two-step electrochemical exfoliation method,the PGO synthesized by the one-step electrochemical exfoliation can better improve the performance of the membrane-electrode-assembly(MEA)based on the polybenzimidazole(PBI)membrane in the HTPEMFC.The doping of 1.5 wt%GO synthesised by electrochemical exfoliation with the 2-step method or reactor method in PBI increased the peak power density by 17.4%or 35.4%compared to MEA based on pure PBI membrane at 150℃,respectively.In addition,the doping of PGO in PBI improves its durability under accelerated stress test(AST).
基金financial support from The University of Manchester to cover his PhD tuition fees for him to carry out this workChina National High-end Foreign Experts Recruitment Plan Project (G2023018001L) for partially supporting the work。
文摘Electrochemical production of hydrogen from water requires the development ofelectrocatalysts that are active,stable,and low-cost for water splitting.To address these challenges,researchers are increasingly exploring binder-free electrocatalytic integratedelectrodes (IEs) as an alternative to conventional powder-based electrode preparation methods,for the former is highly desirable to improve the catalytic activity and long-term stability for large-scale applications of electrocatalysts.Herein,we demonstrate a laser-inducedhydrothermal reaction (LIHR) technique to grow NiMoO4nanosheets on nickel foam,which is then calcined under H2/Ar mixed gases to prepare the IE IE-NiMo-LR.This electrode exhibits superior hydrogen evolution reaction performance,requiring overpotentials of 59,116 and143 mV to achieve current densities of 100,500 and 1000 mA·cm-2.During the 350 h chronopotentiometry test at current densities of 100 and 500 m A·cm-2,the overpotentialremains essentially unchanged.In addition,NiFe-layered double hydroxide grown on Ni foam is also fabricated with the same LIHR method and coupled with IE-NiMo-IR to achieve water splitting.This combination exhibits excellent durability under industrial current density.The energy consumption and production efficiency of the LIHR method are systematicallycompared with the conventional hydrothermal method.The LIHR method significantly improves the production rate by over 19 times,while consuming only 27.78%of the total energy required by conventional hydrothermal methods to achieve the same production.
文摘The goal of this study was to determine whether mutation of the Mn-binding site of wild-type recombinant Phlebia radiata manganese peroxidase 3 affected the pH-dependence kinetic parameters. pH range investigated was 2.5 – 12.0. The catalytic efficiency of the mutant enzymes at high and low pH in comparison to the wild-type was investigated using standard rPr-MnP3 protocol. Wild-type recombinant Phlebia radiata MnP3 enzyme showed optimal activity with Mn (II) as substrate at pH 5.0 and remained moderately active (approximately 40%) in the pH range of 6.0 - 9.0. The rPr-MnP3 mutants’ maximum activity ranged between 5.5 and 8.0. Wild-type and mutants rPr-MnP3 enzymes exhibited a similar pH profile with optimum pH of 3.0 for ABTS oxidation. Mutation has severely decreased the catalytic efficiency for Mn (II) oxidation at pH 5.0. The rPr-MnP3 enzymes showed enhanced affinity for Mn (II) at alkaline pH and a more alkaline range for catalysis than ever reported for any Manganese Peroxidase. This study reveals that at higher pH, rPr-MnP3 can function with alternative ligands in the Mn (II) site and does not have an absolutely obligate requirement for an all carboxylate ligand set. These results further strongly confirm that Mn<sup>2+</sup> binding site is the only productive catalytic site for Mn (II) oxidation.
文摘This investigation is aimed at understanding the specific role of pH and calcium ions on the activity and stability of wild-type recombinant Phlebia radiata manganese peroxidase 3 (rPr-MnP3). The pH-dependent cycle of reactions for rPr-MnP3 was evaluated by investigating time-dependent changes in the activity and electronic absorption spectrum of rPr-MnP3.The rPr-MnP3 had maximum efficacy (kcat/Km) for Mn (II) oxidation at pH 5.0 and 3.0 for oxidation of ABTS. Raising the pH of a solution of resting rPr-MnP3 from pH 6.7 (form XH) to pH 8.6 (form X<sup>−</sup>), a rapid alkaline transition occurs. Leaving the X<sup>−</sup> form of the enzyme at pH 8.6, it slowly becomes converted to a third form of the enzyme Y<sup>−</sup>, which returned to the original XH form of the enzyme at pH 6.7. Recovery of form XH from form Y<sup>−</sup> occurred through an intermediate Z form. The pH inactivation of rPr-MnP3 followed first-order kinetics. The rate of formation of XH from Z is pH-dependent and biphasic in nature, with measured rate constants (k) = 0.25 min<sup>−1</sup>, and half-life (T<sub>1/2</sub>) = 2.8 min. The pH-dependent properties observed may be indicative of a greater degree of conformational flexibility at rPr-MnP3 active site due to disruption of the haem-linked hydrogen-bonding network in the distal haem pocket. Calcium ions were observed to significantly stabilised the enzyme’s spectral features and reduce the loss of activity during the alkaline pH transition. Calcium ions enhance the recovery of the initial activity but cannot prevent the final time-dependent irreversible denaturation and aggregation.
文摘Post-consumer polymeric wastes in form of low-density polyethylene (LDPE) can now be considered suitable as a precursor for the synthesis of low-cost activated carbon (AC). This study produced AC from LDPE using sulphuric acid (H<sub>2</sub>SO<sub>4</sub>) and potassium hydroxide (KOH) as the activating agent. The reaction conditions for pyrolysis were varied in the range of 0.50 - 2.00 M, 400<span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#ffffff;"="">°</span>C - 500<span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#ffffff;"="">°</span>C, and 45 - 60 minutes. Physico-chemical investigations reveal that AC yield is significantly dependent on both carbonization temperatures and time. The obtained optimum values of 446.50<span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#ffffff;"="">°</span>C and 51.09 mins gave a yield of 24% for the base-activated carbon. The high iodine numbers obtained strongly indicate the presence of large surface area and pore volumes is further confirmed using the Scanning Electron Microscopy (SEM) analysis which reveals the presence of pores on the external surface of the carbons. Fourier Transform Infrared Technique (FTIR) analysis further shows that the synthesized compounds are purely carbon with rich oxy-gen-surface complexes on the surface which is as a result of the introduction of the chemical oxidizing agents. The produced carbons were found to have high adsorption affinity for selected inorganic ions which are: Mn<sup>7+</sup>, Co<sup>2+</sup>, and Cr<sup>6+</sup>. Adsorption isotherm results show the adsorption process to be favourable with the Langmuir isotherm parameter RL having values of <1, while the Freudlich adsorption model was found to perfectly fit the data at selected adsorbent dosages and adsorbate concentrations. The pseu-do-second-order model provides the best correlation for the kinetic analysis. The acid-activated carbon was found to have better adsorption capacities than the base-activated carbon.
基金supported by National Natural Science Foundation of China(Nos.42002171,42172159)China Postdoctoral Science Foundation(Nos.2020TQ0299,2020M682520)Postdoctoral Innovation Science Foundation of Hubei Province of China.
文摘The transverse relaxation time (T_(2)) cut-off value plays a crucial role in nuclear magnetic resonance for identifying movable and immovable boundaries, evaluating permeability, and determining fluid saturation in petrophysical characterization of petroleum reservoirs. This study focuses on the systematic analysis of T_(2) spectra and T_(2) cut-off values in low-permeability reservoir rocks. Analysis of 36 low-permeability cores revealed a wide distribution of T_(2) cut-off values, ranging from 7 to 50 ms. Additionally, the T_(2) spectra exhibited multimodal characteristics, predominantly displaying unimodal and bimodal morphologies, with a few trimodal morphologies, which are inherently influenced by different pore types. Fractal characteristics of pore structure in fully water-saturated cores were captured through the T_(2) spectra, which were calculated using generalized fractal and multifractal theories. To augment the limited dataset of 36 cores, the synthetic minority oversampling technique was employed. Models for evaluating the T_(2) cut-off value were separately developed based on the classified T_(2) spectra, considering the number of peaks, and utilizing generalized fractal dimensions at the weight <0 and the singular intensity range. The underlying mechanism is that the singular intensity and generalized fractal dimensions at the weight <0 can detect the T_(2) spectral shift. However, the T_(2) spectral shift has negligible effects on multifractal spectrum function difference and generalized fractal dimensions at the weight >0. The primary objective of this work is to gain insights into the relationship between the kurtosis of the T_(2) spectrum and pore types, as well as to predict the T_(2) cut-off value of low-permeability rocks using machine learning and data augmentation techniques.
基金funding from the European Union’s Hori-zon 2020 research and innovation programme under grant agree-ment No 872102H.X.thanks The University of Manchester Presi-dent’s Doctoral Scholar Award and the China Scholarship Council(file no.201606150068)for supporting her PhD research.
文摘Bioethanol produced via valorisation of renewable biomass is of great interest to many industries.The increased availability and decreased cost of bioethanol make it a promising platform molecule to produce a wide range of value-added chemicals and fuels via the catalytic conversions.This paper provides a comprehensive review of catalytic conversions of bioethanol to a variety of chemicals/fuels such as hydrogen,C_(2)-C_(4)olefins,gasoline and small oxygenates.Specifically,the focus was placed on the relationship between the catalyst property(such as pore structure,acidity,active metal sites,and catalyst supports)and the catalytic performance(including catalyst activity and stability),as well as the reaction mechanisms involved.Future research avenues on the catalyst design for improving catalytic valorisation of bioethanol are also discussed.
基金the China Scholarship Council(CSC,file no.201706950035)University of Manchester joint studentship for supporting her PhD researchthe CSC for her academic visiting fellowship at The University of Manchester(file no.201708440477)the Foundation of Department of Education of Guangdong Province(No.2017KZDXM085,2018KZDXM070)。
文摘Hydrogen(H2)production from photocatalytic reforming of cellulose is a promising way for sustainable H2 to be generated.Herein,we report a systematic study of the photocatalytic reforming of cellulose over Pt/m-TiO2(i.e.mixed TiO2,80%of anatase and 20%of rutile)catalysts in water.The optimum operation condition was established by studying the effect of Pt loading,catalyst concentration,cellulose concentration and reaction temperature on the gas production rate of H2(r(H2))and CO2(r(CO2)),suggesting an optimum operation condition at 40°C with 1.0 g·L^-1of cellulose and 0.75 g·L^-1of 0.16-Pt/m-TiO2 catalyst(with 0.16 wt%Pt loadting)to achieve a relatively sound photocatalytic performance with rH2=9.95μmol·h^-1.It is also shown that although the photoreforming of cellulose was operated at a relatively mild condition(i.e.with an UV-A lamp irradiation at40°C in the aqueous system),a low loading of Pt at^0.16 wt%on m-TiO2 could promote the H2 production effectively.Additionally,by comparing the reaction order expressed from both r(H2)(a1)and r(CO2)(a2)with respect to cellulose and water,the possible mechanism of H2 production was proposed.
基金funding from European Union's Horizon 2020 research and innovation programme under grant agreement No.872102financial support by the Petroleum Technology Development Fund(PTDF),Nigeria(PTDF/ED/OSS/PHD/IA/1209/17)+2 种基金financial support from the European Commission Marie Sklodowska-Curie Individual Fellowship(H2020-MSCAIF-NTPleasure-748196)the Chinese Scholarship Council(CSC)for her academic visiting fellowship at the University of Manchester(No.201708440477)the Foundation of Department of Education of Guangdong Province(Nos.2017KZDXM085,2018KZDXM070)。
文摘Excess crude glycerol derived as a by-product from biodiesel industry prompts the need to valorise glycerol to value-added chemicals.In this context,catalytic steam reforming of glycerol(SRG) was proposed as a promising and sustainable alternative for producing renewable hydrogen(H2).Herein,the development of nickel(Ni) supported on ceria-modified mesoporous γ-alumina(γ-Al2 O3) catalysts and their applications in catalytic SRG(at550-750℃ atmospheric pressure and weight hourly space velocity,WHSV,of 44,122 ml·g^-1·h^-1(STP)) is presented.Properties of the developed catalysts were characterised using many technique s.The findings show that ceria modification improved Ni dispersion on γ-Al2 O3 catalyst support with highly active small Ni particles,which led to a remarkable catalytic performance with the total glycerol conversion(ca.99%),glycerol conversion into gaseous products(ca.77%) and H2 yield(ca.62%).The formation rate for H2 production(14.4 ×10^(-5)mol·s^-1·g^-1, TOF(H2)=3412 s^-1) was significantly improved with the Ni@12 Ce-Al2 O3 catalyst,representing nearly a 2-fold increase compared with that of the conventional Ni@AI2 O3 catalyst.In addition,the developed catalyst also exhibited comparatively high stability(for 12 h) and coke resistance ability.
文摘This special issue of the Chinese Journal of Chemical Engineering(CJCh E)concerns with the current progress in advanced energy technologies and materials related to chemical science and technology,especially the work in the field of renewable energy,energy storage,clean and efficient utilization of energy,aligning well to the scope of this Journal.The world is moving towards a sustainable,clean and low-carbon future via‘Energy Transition',i.e..
文摘Following the CSCST-25 Special Issue[1]we continued this issue based on the 26th CSCST-SCI annual conference(CSCST-SCI 26),which was held at the Society of Chemical Industry(SCI)headquarter,14/15 Belgrave Square,London SW 1X 8PS on the 4th and 5th Septem ber 2019.The annual conference had 4 sessions with 20 oral and 14 poster presentations,which featured several plenary and keynote lectures by national and international em inent speakers.
基金funded by the UK Research Council EPSRC EP/009050/1。
文摘High-temperature proton exchange membrane fuel cells(HT-PEMFCs)are pursued worldwide as efficient energy conversion devices.Great efforts have been made in the area of designing and developing phosphoric acid(PA)-based proton exchange membrane(PEM)of HT-PEMFCs.This review focuses on recent advances in the limitations of acid-based PEM(acid leaching,oxidative degradation,and mechanical degradation)and the approaches mitigating the membrane degradation.Preparing multilayer or polymers with continuous network,adding hygroscopic inorganic materials,and introducing PA doping sites or covalent interactions with PA can effectively reduce acid leaching.Membrane oxidative degradation can be alleviated by synthesizing crosslinked or branched polymers,and introducing antioxidative groups or highly oxidative stable materials.Crosslinking to get a compact structure,blending with stable polymers and inorganic materials,preparing polymer with high molecular weight,and fabricating the polymer with PA doping sites away from backbones,are recommended to improve the membrane mechanical strength.Also,by comparing the running hours and decay rate,three current approaches,1.crosslinking via thermally curing or polymeric crosslinker,2.incorporating hygroscopic inorganic materials,3.increasing membrane layers or introducing strong basic groups and electron-withdrawing groups,have been concluded to be promising approaches to improve the durability of HT-PEMFCs.The overall aim of this review is to explore the existing degradation challenges and opportunities to serve as a solid basis for the deployment in the fuel cell market.
基金the financial support from the Jiangsu Specially-Appointed Professors Program and the European Commission under the Marie Skłodowska-Curie Individual Fellowship(H2020-MSCA-IFNTPleasure-748196).
文摘C1 chemistrymainly involves the catalytic transformation of C1molecules(i.e.,CO,CO2,CH4 and CH3OH),which usually encounters thermodynamic and/or kinetic limitations.To address these limitations,non-thermal plasma(NTP)activated heterogeneous catalysis offers a number of advantages,such as relatively mild reaction conditions and energy efficiency,in comparison to the conventional thermal catalysis.This review presents the state-of-the-art for the application of NTP-catalysis towards C1 chemistry,including the CO2 hydrogenation,reforming of CH4 and CH3OH,and water-gas shift(WGS)reaction.In the hybrid NTP-catalyst system,the plasma-catalyst interactions aremultifaceted.Accordingly,this reviewalso includes a brief discussion on the fundamental research into themechanisms of NTP activated catalytic C1 chemistry,such as the advanced characterisation methods(e.g.,in situ diffuse reflectance infrared Fourier transform spectroscopy,DRIFTS),temperatureprogrammed plasma surface reaction(TPPSR),kinetic studies.Finally,prospects for the future research on the development of tailor-made catalysts for NTP-catalysis systems(which will enable the further understanding of its mechanism)and the translation of the hybrid technique to practical applications of catalytic C1 chemistry are discussed.
基金the EPSRC grant EP/009050/1supported by the Henry Royce Institute for Advanced Materials which is funded by EPSRC grants EP/S019367/1,EP/P025021/1,EP/R00661X/1 and EP/P025498/1.
文摘Silica nanosheets(SN)derived from natural vermiculite(Verm)were successfully incorporated into polyethersulfone-polyvinylpyrrolidone(PES-PVP)polymer to fabricate high-temperature proton exchange membranes(HT-PEMs).The content of SN filler was varied(0.1-0.75 wt%)to study its influence on proton conductivity,power density and durability.Benefiting from the hydroxyl groups of SN that enable the formation of additional proton-transferring pathways,the inorganic-organic membrane displayed enhanced proton conductivity of 48.2 mS/cm and power density of 495 mW/cm^(2) at 150℃ without humidification when the content of SN is 0.25 wt%.Furthermore,exfoliated SN(E-SN)and sulfonated SN(S-SN),which were fabricated by a liquid-phase exfoliation method and silane condensation,respectively,were embedded in PES-PVP polymer matrix by a simple blending method.Due to the significant contribution from sulfonic groups in S-SN,the membrane with 0.25 wt%S-SN reached the highest proton conductivity of51.5 mS/cm and peak power density of 546 mW/cm^(2) at150℃,48%higher than the pristine PES-PVP membranes.Compared to unaltered PES-PVP membrane,SN added hybrid composite membrane demonstrated excellent durability for the fuel cell at 150℃.Using a facile method to prepare 2D SN from natural clay minerals,the strategy of exfoliation and functionalization of SN can be potentially used in the production of HT-PEMs.
基金supported by the Engineering and Physical Sciences Research Council (EPSRC) EP/P009050/1 and EP/S021531/1the Henry Royce Institute for Advanced Materials, funded through the EPSRC grants EP/R00661X/1, EP/S019367/1, EP/P025021/1 and EP/P025498/1funding from the European Commission H2020ERC Starter grant Evolu TEM (715502)。
文摘Nitrogen doping of the carbon is an important method to improve the performance and durability of catalysts for proton exchange membrane fuel cells by platinum–nitrogen and carbon–nitrogen bonds. This study shows that p-phenyl groups and graphitic N acting bridges linking platinum and the graphene/carbon black(the ratio graphene/carbon black = 2/3) hybrid support materials achieved the average size of platinum nanoparticles with(4.88 ± 1.79) nm. It improved the performance of the lower-temperature hydrogen fuel cell up to 0.934 W cm^(-2) at 0.60 V, which is 1.55 times greater than that of commercial Pt/C. Doping also enhanced the interaction between Pt and the support materials, and the resistance to corrosion, thus improving the durability of the low-temperature hydrogen fuel cell with a much lower decay of 10 mV at 0.80 A cm^(-2) after 30 k cycles of an in-situ accelerated stress test of catalyst degradation than that of 92 mV in Pt/C, which achieves the target of Department of Energy(<30 mV). Meanwhile,Pt/Nr EGO_(2)-CB_(3) remains 78% of initial power density at 1.5 A cm^(-2) after 5 k cycles of in-situ accelerated stress test of carbon corrosion, which is more stable than the power density of commercial Pt/C, keeping only 54% after accelerated stress test.
基金financial support from the Key Projects of Natural Science Foundation of Liaoning Province(2018010047-301)the Shenyang National Laboratory for Materials Science for his research(Y8L6641161)+1 种基金financial support from the National Key R&D Program of China(2016YFB0501303)funding from European Union's Horizon 2020 research and innovation programme under grant agreement No.872102。
文摘Silicalite-1(S1)foam was functionalized by supporting manganese-cobalt(Mn-Co)mixed oxides to develop the structured hierarchical catalyst(Mn-Co@SlF)for catalytic combustion for the first time.The self-supporting S1 foam with hierarchical porosity was prepared via hydrothermal synthesis with polyurethane(PU)foam as the template.Subsequently,Mn-Co oxide nano sheets were uniformly grown on the surface of S1 foams under hydrothermal conditions to prepare the structured hierarchical catalyst with specific surface area of 354 m^2·g^-1,micropore volume of 0.141 cm^3·g^-1 and total pore volume of 0.217 cm3·g^-1,as well as a good capacity to adsorb toluene(1.7 mmol·g^-1 at p/p0=0.99).Comparative catalytic combustion of toluene of over developed structured catalyst Mn-Co@SlF was performed against the control catalysts of bulk Mn-Co@S1(i.e.,the crushed Mn-Co@SlF)and unsupported Mn-Co oxides(i.e.,Mn-Co).Mn-Co@SlF exhibited comparatively the best catalytic performance,that is,complete and stable toluene conversion at 2480 C over 65 h due to the synergy between Mn-Co oxides and S1 foam,which provided a large number of oxygen vacancies,high redox capacity.In addition,the hierarchical porous structure also improved the accessibility of active sites and facilitated the global mass transfer across the catalyst bed,being beneficial to the catalysis and catalyst longevity.
文摘Body-scanning exploiting 3-D imaging has revolutionised diagnostics and treatment in medicine. Process engineers would like to be similarly able to image chemical process units in 3-D, but without the Lmulti-million price tag. UMIST and Leeds University have together, through the Virtual Centre for Industrial Process Tomography （http：//www.vcipt.org）, pioneered several electrical process tomography techniques and used them in a variety of applications. Illustrations are presented to show how electrical resistance tomography （ERT） has been developed for typical stirred vessels widely encountered in batch process manufacturing. The technique is potentially fast and inexpensive and capable of imaging both dynamic and pseudo-stationary processes. Examples from UMIST＇s two-tonne vessel will be presented for miscible tracer mixing, as well as gas-liquid and solid-liquid mixing.
基金the Spanish Ministerio de Economía y Competitividadthe European Social Fund for her Ramon y Cajal Fellowship (RYC2019-027060-I/AEI/10.13039/5011 00011033)the China Scholarship Council (202006240076)-University of Manchester joint studentship
文摘With the continuous growth of the world population,the demand for fresh water is ever increasing.Water desalination is a means of producing fresh water from saline water,and one of the proposed solutions in the scientific community for solving the current global freshwater shortage.Adsorption is foreseen as a promising technology for desalination due to its relatively low energy requirements,low environmental impact,low cost and high salt removal efficiency.More importantly,chemicals are not required in adsorption processes.Active carbons,zeolites,carbon nanostructures,graphene and coordination framework materials are amongst the most investigated adsorbents for adsorption desalination,which show different performances regarding adsorption rate,adsorption capacity,stability and recyclability.In this review,the latest adsorbent materials with their features are assessed(using metrics)and commented critically,and the current trend for their development is discussed.The adsorption mode is also reviewed,which can provide guidance for the design of adsorbents from the engineering application point of view.
