Journal of the American Chemical Society
·
2022
·
IF 16.383
Xiao Liu,Zhi Chen,Suxian Xu,Guoquan Liu,Yong Zhu,Xiaoqiang Yu,Licheng Sun,Fei Li
In a photoelectrochemical (PEC) cell, the production of solar fuels such as hydrogen is often accompanied either by the oxidation of water or by the oxidation of organic substrates. In this study, we report bromide-mediated PEC oxidation of alkenes at a mesoporous BiVO4 photoanode and simultaneous hydrogen evolution at the cathode using water as an oxygen source. NaBr as a redox mediator was demonstrated to play a dual role in the PEC organic synthesis, which facilitates the selective oxidation of alkenes into epoxides and suppresses the photocorrosion of BiVO4 in water. This method enables a near-quantitative yield and 100% selectivity for the conversion of water-soluble alkenes into their epoxides in H2O/CH3CN solution (v/v, 4/1) under simulated sunlight without the use of noble metal-containing catalysts or toxic oxidants. The maximum solar-to-electricity efficiency of 0.58% was obtained at 0.39 V vs Ag/AgCl. The obtained epoxide products such as glycidol are important building blocks of the chemical industry. Our results provide an energy-saving and environment-benign approach for producing value-added chemicals coupled with solar fuel generation.
研究领域:
化学工程
·
环境科学
·
能源科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CATALYSIS
·
2015
·
IF 6.921
Bao Zhang,Jun Li,Bingqing Zhang,Ruifeng Chong,Rengui Li,Bo Yuan,Sheng-Mei Lu,Can Li
Photocatalytic selective oxidation represents an environment-friendly strategy for chemical transformation. Herein, we report the oxidation of sulfides into sulfoxides with high selectivity (up to 99%) on Pt/BiVO 4 photocatalyst in water under visible light illumination. The system exhibited excellent performance for the oxidation of sulfides in water compared with organic solvents. Isotopic oxygen (H 2 18 O) experiments clearly revealed that the oxygen atoms in the sulfoxide were mainly from water. Electron paramagnetic resonance demonstrated that the reactive oxygen species were the peroxy species, which were generated from water oxidation on BiVO 4 via the two-electron pathway. Dioxygen was reduced to water through proton-coupled electron transfer.
研究领域:
化学
·
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2023
·
IF 7.3
Liyong Ding,Yukun Zhao,Youji Li,Chengsheng Ge,Liang Lv,Hongwei Ji,Wenjing Song,Chuncheng Chen,Jincai Zhao
During TiO 2 -based photocatalysis, the presence of water usually leads to the unselective degradation of organic compounds due to the uncontrollable formation of water-derived radical species. Here we report that the presence of water dramatically enhances the selectivity in photocatalytic oxidation of sulfides to sulfoxides over TiO 2 . H 2 18 O-isotope labelling experiments reveal that both O 2 and H 2 18 O contribute to the oxygen atoms in the formed sulfoxides and sulfones. Moreover, at the beginning of the oxidation of sulfides, water serves as the main source of the oxygen atom, while the contribution of O 2 increases with the irradiation time. We uncover two roles of water in sulfides oxidation: to act as oxygen source in the oxidation of sulfides to sulfoxides; to provide protons to inhibit the further oxidation of sulfoxides. This study deepens our understanding of roles of water in photocatalytic oxidation of sulfides and offers a new strategy to optimize photocatalytic selective oxidation .
研究领域:
化学
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2024
·
IF 6.5
Ziru Wang,Jinxiu Zhai,Yali Zhao,Wei Wang,Zhiyi Lu,Peilei He
The electrocatalytic epoxidation directly using water as oxygen source is considered as a sustainable strategy to achieve epoxide production under ambient conditions. However, it is challenging to develop non-noble metal based heterogeneous electrocatalysts for efficient epoxidation with a deep understanding of the structure–activity relationships. In this work, we report a Weakley-polyoxometalate Na 10 [Co 4 (H 2 O) 2 (PW 9 O 34 ) 2 ] (Co 4 P 2 W 18 ) with high efficiency toward electrocatalytic epoxidation of cyclooctene via directly transfer oxygen atom from water. A significantly higher faradaic efficiency of cyclooctene oxide was achieved over Co 4 P 2 W 18 than a Keggin type Co substituted polyoxometalate Na 5 [Co(H 2 O)PW 11 O 39 ] (CoPW 11 ) and some other typical electrocatalysts including RuO 2 , IrO 2 , and Co 3 O 4 in our system. Experimental results and theoretical calculation indicate that the oxygen atom directly transfers from water for the epoxidation of cyclooctene via the cleavage of O−H of pre-adsorbed water as the rate-determined step. Further calculation demonstrates that the water and cyclooctene were adsorbed by Co site and their adjacent terminal oxygen atom during the epoxidation reaction. With the assistance of this terminal oxygen atom for adsorption and as an electron capture center, lower energy barriers for activation of water and cyclooctene are observed on Co 4 P 2 W 18 than on CoPW 11 . Our study provides atomic insight into how structure affects catalytic activity, which benefits designing efficient electrocatalysts.
研究领域:
催化
·
电化学
·
材料科学
·
可持续化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Saudi Chemical Society
·
2023
·
IF 5.6
Zhong-Lin Zang,Qi Wang,Zhi-Chao Dong,Sheng-Yao Huang,Hao-Zeng Wu,Cheng-He Zhou,Gui-Xin Cai
α,β -Unsaturated ketone is one of the important building blocks of the plenty of alkaloids, spices and pharmaceutical agents. Herein, we describe a peroxide-free electrochemical strategy to realize site-selective allylic C − H oxidation for the synthesis of α,β -unsaturated ketones. This electrochemically driven oxidation exhibits a broad substrate scope. Mechanistic investigations of this reaction uncovered HOAc and H 2 O as the oxygen source to achieve peroxide-free electrochemical allylic C − H oxidation.
研究领域:
有机化学
·
电化学
·
合成化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）