Photocatalytic oxidation of water is a promising method to realize large-scale H2O2 production without a hazardous and energy-intensive process. In this study, we introduce a Pt/TiO2(anatase) photocatalyst to construc...Photocatalytic oxidation of water is a promising method to realize large-scale H2O2 production without a hazardous and energy-intensive process. In this study, we introduce a Pt/TiO2(anatase) photocatalyst to construct a simple and environmentally friendly system to achieve simultaneous H2 and H2O2 production. Both H2 and H2O2 are high-value chemicals, and their separation is automatic. Even without the assistance of a sacrificial agent, the system can reach an efficiency of 7410 and 5096 μmol g^-1 h^–1 (first 1 h) for H2 and H2O2, respectively, which is much higher than that of a commercial Pt/TiO2(anatase) system that has a similar morphology. This exceptional activity is attributed to the more favorable two-electron oxidation of water to H2O2, compared with the four-electron oxidation of water to O2.展开更多
To optimize the technological parameter of underground coal gasification （UCG）, the experimental results of air gasification, air-steam gasification, oxygen-enrichment steam gasification, pure oxygen steam gasificat...To optimize the technological parameter of underground coal gasification （UCG）, the experimental results of air gasification, air-steam gasification, oxygen-enrichment steam gasification, pure oxygen steam gasification and two-stage gasification were studied contrastively based on field trial at the Huating UCG project. The results indicate that the average low heat value of gas from air experiment is the lowest （4.1 MJ/Nm3） and the water gas from two-stage gasification experiment is the highest （10.72 MJ/Nm3）. The gas productivity of air gasification is the highest and the pure oxygen steam gasification is the lowest. The gasification efficiency of air gasification, air-steam gasification, oxygen-enriched steam gasification, pure oxygen steam gasification and two-stage gasification is listed in ascending order, ranging from 69.88% to 84.81%. Described a contract study on results of a field test using steam and various levels of oxygen enrichment of 21%, 32%, 42% and 100%. The results show that, with the increasing of O2 content in gasifying agents, the gas caloricity rises, and the optimal O2 concentration range to increase the gas caloricity is 30%-40%. Meanwhile, the consumption of O2 and steam increase, and the air consumption and steam decomposition efficiency fall.展开更多
Direct N2O decomposition has been investigated over bare NiO and a series of its alkali-promoted catalysts. These catalysts were characterized by X-ray diffractometry, X-ray photoelectron spectroscopy （XPS） and fiel...Direct N2O decomposition has been investigated over bare NiO and a series of its alkali-promoted catalysts. These catalysts were characterized by X-ray diffractometry, X-ray photoelectron spectroscopy （XPS） and field emission scanning electron microscopy. XPS analysis revealed that surface nickel is present in three forms： metal particles, NiO and Ni（OH）2. It is suggested that nickel（0） valent atoms are essential for the interaction with N2O molecules at the catalyst surfaces. Bare NiO exhibited a very low N2O decomposition reactivity. However, the alkali-containing catalysts exhibited a marked activity enhancement.展开更多
Hydrogen is a promising sustainable energy to replace fossil fuels owning to its high specific energy and environmental friendliness.Alkaline water electrolysis has been considered as one of the most prospective techn...Hydrogen is a promising sustainable energy to replace fossil fuels owning to its high specific energy and environmental friendliness.Alkaline water electrolysis has been considered as one of the most prospective technologies for large scale hydrogen production.To boost the sluggish kinetics of hydrogen evolution reaction(HER)in alkaline media,abundant materials have been designed and fabricated.Herein,we summarize the key achievements in the development of layered transition-metal hydroxides[TM(OH)x]for efficient alkaline HER.Based on the structure of TM(OH)x,the mechanism of synergistic effect between TM(OH)x and HER active materials is illuminated firstly.Then,recent progress of TM(OH)x-based HER catalysts to optimize the synergistic effect are categorized as TM(OH)x and active materials,including species,structure,morphology and interaction relationship.Furthermore,TM(OH)x-based overall water splitting electrocatalysts and electrodes are summarized in the design principles for high activity and stability.Finally,some of key challenges for further developments and applications of hydrogen production are proposed.展开更多
Lignin is a group of phenolic polymers which is abundant in the woody tissues of vascular plants,and is essentially absent from all other living organisms.It has therefore been accepted as a tracer for terrestrial org...Lignin is a group of phenolic polymers which is abundant in the woody tissues of vascular plants,and is essentially absent from all other living organisms.It has therefore been accepted as a tracer for terrestrial organic carbon(TOC) in marine environment since the 1970s.Lignin polymers are not amenable to direct chemical analysis without prior isolation.This review focused on the methods of chemical decomposition,extraction,derivatization and detection of lignin in marine environment.We described and compared several chemical decomposition methods,including nitrobenzene oxidation,alkaline cupric oxide(CuO) oxidation and thermochemolysis,and detection methods such as gas chromatography(GC),gas chromatography-mass spectrometry(GC-MS),high performance liquid chromatography(HPLC) and so on.Possible improvement of lignin analysis and the application prospects of this tracer were also discussed.展开更多
基金supported by the National Natural Science Foundation of China(21703046)the National Key R&D of China(2016YFF0203803 and 2016YFA0200902)~~
文摘Photocatalytic oxidation of water is a promising method to realize large-scale H2O2 production without a hazardous and energy-intensive process. In this study, we introduce a Pt/TiO2(anatase) photocatalyst to construct a simple and environmentally friendly system to achieve simultaneous H2 and H2O2 production. Both H2 and H2O2 are high-value chemicals, and their separation is automatic. Even without the assistance of a sacrificial agent, the system can reach an efficiency of 7410 and 5096 μmol g^-1 h^–1 (first 1 h) for H2 and H2O2, respectively, which is much higher than that of a commercial Pt/TiO2(anatase) system that has a similar morphology. This exceptional activity is attributed to the more favorable two-electron oxidation of water to H2O2, compared with the four-electron oxidation of water to O2.
文摘To optimize the technological parameter of underground coal gasification （UCG）, the experimental results of air gasification, air-steam gasification, oxygen-enrichment steam gasification, pure oxygen steam gasification and two-stage gasification were studied contrastively based on field trial at the Huating UCG project. The results indicate that the average low heat value of gas from air experiment is the lowest （4.1 MJ/Nm3） and the water gas from two-stage gasification experiment is the highest （10.72 MJ/Nm3）. The gas productivity of air gasification is the highest and the pure oxygen steam gasification is the lowest. The gasification efficiency of air gasification, air-steam gasification, oxygen-enriched steam gasification, pure oxygen steam gasification and two-stage gasification is listed in ascending order, ranging from 69.88% to 84.81%. Described a contract study on results of a field test using steam and various levels of oxygen enrichment of 21%, 32%, 42% and 100%. The results show that, with the increasing of O2 content in gasifying agents, the gas caloricity rises, and the optimal O2 concentration range to increase the gas caloricity is 30%-40%. Meanwhile, the consumption of O2 and steam increase, and the air consumption and steam decomposition efficiency fall.
文摘Direct N2O decomposition has been investigated over bare NiO and a series of its alkali-promoted catalysts. These catalysts were characterized by X-ray diffractometry, X-ray photoelectron spectroscopy （XPS） and field emission scanning electron microscopy. XPS analysis revealed that surface nickel is present in three forms： metal particles, NiO and Ni（OH）2. It is suggested that nickel（0） valent atoms are essential for the interaction with N2O molecules at the catalyst surfaces. Bare NiO exhibited a very low N2O decomposition reactivity. However, the alkali-containing catalysts exhibited a marked activity enhancement.
基金supported by the National Key Research and Development Program(2017YFC0306403)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA09030104,XDA22010601)the Youth Innovation Promotion Association of the Chinese Academy of Sciences~~
文摘Hydrogen is a promising sustainable energy to replace fossil fuels owning to its high specific energy and environmental friendliness.Alkaline water electrolysis has been considered as one of the most prospective technologies for large scale hydrogen production.To boost the sluggish kinetics of hydrogen evolution reaction(HER)in alkaline media,abundant materials have been designed and fabricated.Herein,we summarize the key achievements in the development of layered transition-metal hydroxides[TM(OH)x]for efficient alkaline HER.Based on the structure of TM(OH)x,the mechanism of synergistic effect between TM(OH)x and HER active materials is illuminated firstly.Then,recent progress of TM(OH)x-based HER catalysts to optimize the synergistic effect are categorized as TM(OH)x and active materials,including species,structure,morphology and interaction relationship.Furthermore,TM(OH)x-based overall water splitting electrocatalysts and electrodes are summarized in the design principles for high activity and stability.Finally,some of key challenges for further developments and applications of hydrogen production are proposed.
基金supported by National Basic Research Program of China (973 Program 2010CB428901)
文摘Lignin is a group of phenolic polymers which is abundant in the woody tissues of vascular plants,and is essentially absent from all other living organisms.It has therefore been accepted as a tracer for terrestrial organic carbon(TOC) in marine environment since the 1970s.Lignin polymers are not amenable to direct chemical analysis without prior isolation.This review focused on the methods of chemical decomposition,extraction,derivatization and detection of lignin in marine environment.We described and compared several chemical decomposition methods,including nitrobenzene oxidation,alkaline cupric oxide(CuO) oxidation and thermochemolysis,and detection methods such as gas chromatography(GC),gas chromatography-mass spectrometry(GC-MS),high performance liquid chromatography(HPLC) and so on.Possible improvement of lignin analysis and the application prospects of this tracer were also discussed.
