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

• Published in: Nano research 2017-10, Vol.10 (10), p.3396-3406
• Main Authors: Zhu, Yuzhen, Gao, Chao, Bai, Song, Chen, Shuangming, Long, Ran, Song, Li, Li, Zhengquan, Xiong, Yujie
• Format: Article
• Language: English
• Subjects: Atomic/Molecular Structure and Spectra; Biomedicine; Biotechnology; Carbon dioxide; CH4; Chemistry and Materials Science; CO2还原; Condensed Matter Physics; Conversion; Hydridation; Hydrogen production; Isotopic labeling; Materials Science; Methane; Nanotechnology; Palladium; Performance enhancement; Photocatalysis; Radioactive labeling; Reduction (metal working); Research Article; 催化剂性能; 光催化还原; 助催化剂; 增强方法; 氢化物; 钯催化剂
• ISSN: 1998-0124; 1998-0000
• DOI: 10.1007/s12274-017-1552-0

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.