Hydriding Pd cocatalysts： An approach to giant enhancement on photocatalytic CO2 reduction into CH4  

作　　者：Yuzhen Zhu Chao Gao Song Bai Shuangming Chen Ran Long Li Song Zhengquan Li Yujie Xiong 

机构地区：[1]Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, College of Chemistry and Life Sciences, Institute of Physical and Chemistry, Zhejiang Normal University, Jinhua 321004, China [2]Hefei National Laboratory for Physical Sciences at the Microscale, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), School of Chemistry and Materials Science, Hefei Science Center (CAS), and National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230026, China

出　　处：《Nano Research》2017年第10期3396-3406,共11页纳米研究（英文版）

基　　金：Acknowledgements This work was financially supported in part by the National Natural Science Foundation of China （Nos. 21471141, U1532135, and 21603191）, CAS Key Research Program of Frontier Sciences （No. QYZDB- SSW-SLH018）, Zhejiang Provincial Natural Science Foundation （No. LQ16B010001）, Recruitment Program of Global Experts, and CAS Hundred Talent Program XAFS measurements were performed at the beamline BL14W1 in the Shanghai Synchrotron Radiation Facility （SSRF）, China.

摘　　要：Photocatalytic reduction of CO2 into high value-added CH4 is a promising solution for energy and environmental crises. Integrating semiconductors with cocatalysts can improve the activities for photocatalytic CO2 reduction; however, most metal cocatalysts mainly produce CO and H2. Herein, we report a cocatalyst hydridation approach for significantly enhancing the photocatalytic reduction of CO2 into CH4. Hydriding Pd cocatalysts into PdH0.43 played a dual role in performance enhancement. As revealed by our isotopic labeling experiments, the PdH0.43 hydride cocatalysts reduced H2 evolution, which suppressed the H2 production and facilitated the conversion of the CO intermediate into the final product： CH4. Meanwhile, hydridation promoted the electron trapping on the cocatalysts, improving the charge separation. This approach increased the photocatalytic selectivity in CH4 production from 3.2% to 63.6% on Pd{100} and from 15.6% to 73.4% on Pd{111}. The results provide insights into photocatalytic mechanism studies and introduce new opportunities for designing materials towards photocatalytic CO2 conversion.Photocatalytic reduction of CO2 into high value-added CH4 is a promising solution for energy and environmental crises. Integrating semiconductors with cocatalysts can improve the activities for photocatalytic CO2 reduction; however, most metal cocatalysts mainly produce CO and H2. Herein, we report a cocatalyst hydridation approach for significantly enhancing the photocatalytic reduction of CO2 into CH4. Hydriding Pd cocatalysts into PdH0.43 played a dual role in performance enhancement. As revealed by our isotopic labeling experiments, the PdH0.43 hydride cocatalysts reduced H2 evolution, which suppressed the H2 production and facilitated the conversion of the CO intermediate into the final product： CH4. Meanwhile, hydridation promoted the electron trapping on the cocatalysts, improving the charge separation. This approach increased the photocatalytic selectivity in CH4 production from 3.2% to 63.6% on Pd{100} and from 15.6% to 73.4% on Pd{111}. The results provide insights into photocatalytic mechanism studies and introduce new opportunities for designing materials towards photocatalytic CO2 conversion.

关 键 词：photocatalysis COCATALYST palladium hydride carbon dioxide methane 

分 类 号：O643.32[理学—物理化学] X131[理学—化学]