O437 2005064168 取代肉桂酸异构体的稳定性和二阶非线性光学性质的 DFT研究=DFT study on the stabilities and second-order nonlinear optical properties of the cinnamic acid isomers [刊,中]/谭克(长春大学环境生态工程学院．吉林。
Rational engineering of oxygen vacancy(VO) at atomic precision is the key to comprehensively understanding the oxygen chemistry of oxide materials for catalytic oxidations. Here, we demonstrate that VO can be spatiall...Rational engineering of oxygen vacancy(VO) at atomic precision is the key to comprehensively understanding the oxygen chemistry of oxide materials for catalytic oxidations. Here, we demonstrate that VO can be spatially confined on the surface through a sophisticated surface hydrogen bond(HB) network.The HB network is constructed between a hydroxyl-rich Bi OCl surface and polyprotic phosphoric acid,which remarkably decreases the formation energy of surface VO by selectively weakening the metal–oxygen bonds in a short range. Thus, surface-confined VO enables us to unambiguously distinguish the intrafacial and suprafacial oxygen species associated with NO oxidation in two classical catalytic systems.Unlike randomly distributed bulk VO that benefits the thermocatalytic NO oxidation and lattice O diffusion by the dominant intrafacial mechanism, surface VOis demonstrated to favor the photocatalytic NO oxidation through a suprafacial scheme by energetically activating surface O2, which should be attributed to the spatial confinement nature of surface VO.展开更多
High-temperature proton exchange membrane(HT-PEM)fuel cells offer more advantages than low-temperature PEM fuel cells.The ideal characteristics of HT-PEMs are high conductivities,low-humidity operation conditions,adeq...High-temperature proton exchange membrane(HT-PEM)fuel cells offer more advantages than low-temperature PEM fuel cells.The ideal characteristics of HT-PEMs are high conductivities,low-humidity operation conditions,adequate mechanical properties,and competitive costs.Various molecular moieties,such as benzimidazole,benzothiazole,imide,and ether ether ketone,have been introduced to polymer chain backbones to satisfy the application requirements for HT-PEMs.The most common sulfonated polymers based on the main chain backbones have been employed to improve the rties.Side group/chain engineering,including the introduction of SO_(3)^(-) on the side chain,grafting,branching,and crosslinking,has been widely applied to HTPEMs to further improve their proton conductivity,thermal stability,and mechanical properties.Currently,phosphoric acid-doped polybenzimidazole is the most successful polymer material for application in HT-PEMs.The compositing/blending modification methods of polymers are effective in obtaining high PA-doping levels and superior mechanical properties.In this review,the current progress of various membrane materials used for HT-PEMs is summarized.The synthesis and performance characteristics of polymers containing specific moieties in the chain backbones applied to HT-PEMs are discussed systemically.Various modification approaches and their deficiencies associated with HT-PEMs are analyzed and clarified.Prospects and future challenges are also presented.展开更多
文摘O437 2005064168 取代肉桂酸异构体的稳定性和二阶非线性光学性质的 DFT研究=DFT study on the stabilities and second-order nonlinear optical properties of the cinnamic acid isomers [刊,中]/谭克(长春大学环境生态工程学院．吉林。
基金the National Key Research and Development Program of China (2016YFA0203000)National Natural Science Funds for Distinguished Young Scholars (21425728)+2 种基金the National Natural Science Foundation of China (21872061)111 Project (B17019)Self-Determined Research Funds of CCNU from the Colleges’ Basic Research and Operation of MOE (CCNU16A02029)。
文摘Rational engineering of oxygen vacancy(VO) at atomic precision is the key to comprehensively understanding the oxygen chemistry of oxide materials for catalytic oxidations. Here, we demonstrate that VO can be spatially confined on the surface through a sophisticated surface hydrogen bond(HB) network.The HB network is constructed between a hydroxyl-rich Bi OCl surface and polyprotic phosphoric acid,which remarkably decreases the formation energy of surface VO by selectively weakening the metal–oxygen bonds in a short range. Thus, surface-confined VO enables us to unambiguously distinguish the intrafacial and suprafacial oxygen species associated with NO oxidation in two classical catalytic systems.Unlike randomly distributed bulk VO that benefits the thermocatalytic NO oxidation and lattice O diffusion by the dominant intrafacial mechanism, surface VOis demonstrated to favor the photocatalytic NO oxidation through a suprafacial scheme by energetically activating surface O2, which should be attributed to the spatial confinement nature of surface VO.
基金supported by the National Key Research and Development Program of China(2019YFC1906602)the National Natural Science Foundation of China(U1904171)+3 种基金the Foundation for"Talent Program"the Open Fund of the State Key Laboratory of Biochemical Engineering,Institute of Process Engineering(IPE)Chinese Academy of Sciences(CAS),the Project Fund of Jiangsu Bingcheng Hydrogen Energy Technology Co.,Ltd.the Young Backbone Teachers Training Program Foundation of Henan University of Technology。
文摘High-temperature proton exchange membrane(HT-PEM)fuel cells offer more advantages than low-temperature PEM fuel cells.The ideal characteristics of HT-PEMs are high conductivities,low-humidity operation conditions,adequate mechanical properties,and competitive costs.Various molecular moieties,such as benzimidazole,benzothiazole,imide,and ether ether ketone,have been introduced to polymer chain backbones to satisfy the application requirements for HT-PEMs.The most common sulfonated polymers based on the main chain backbones have been employed to improve the rties.Side group/chain engineering,including the introduction of SO_(3)^(-) on the side chain,grafting,branching,and crosslinking,has been widely applied to HTPEMs to further improve their proton conductivity,thermal stability,and mechanical properties.Currently,phosphoric acid-doped polybenzimidazole is the most successful polymer material for application in HT-PEMs.The compositing/blending modification methods of polymers are effective in obtaining high PA-doping levels and superior mechanical properties.In this review,the current progress of various membrane materials used for HT-PEMs is summarized.The synthesis and performance characteristics of polymers containing specific moieties in the chain backbones applied to HT-PEMs are discussed systemically.Various modification approaches and their deficiencies associated with HT-PEMs are analyzed and clarified.Prospects and future challenges are also presented.
