Dong Hao, Zhang Lei, Li Lulu, Deng Wanyu, Hu Congling, Zhao Zhi-Jian, Gong Jinlong
Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, P. R. China.
Collaborative Innovation Center of Chemical Science and Engineering, Tianjin University, Tianjin, 300072, P. R. China.
Small. 2019 Apr;15(17):e1900289. doi: 10.1002/smll.201900289. Epub 2019 Apr 2.
The electroreduction of CO to CO provides a potential way to solve the environmental problems caused by excess fossil fuel utilization. Loading transition metals on metal oxides is an efficient strategy for CO electroreduction as well as for reducing metal usage. However, it needs a great potential to overcome the energy barrier to increase CO selectivity. This paper describes how 8.7 wt% gold nanoparticles (NPs) loaded on CeO nanosheets (NSs) with high Ce concentration effectively decrease the overpotential for CO electroreduction. The 3.6 nm gold NPs on CeO NSs containing 47.3% Ce achieve CO faradaic efficiency of 90.1% at -0.5 V in 0.1 m KHCO solution. Furthermore, the CO electroreduction activity shows a strong relationship with the fractions of Ce on Au-CeO NSs, which has never been reported. In situ surface-enhanced infrared absorption spectroscopy shows that Au-CeO NSs with high Ce concentration promote CO activation and *COOH formation. Theoretical calculations also indicate that the improved performance is attributed to the enhanced *COOH formation on Au-CeO NSs with high Ce fraction.
将CO电还原为CO为解决因过度使用化石燃料而导致的环境问题提供了一条潜在途径。在金属氧化物上负载过渡金属是一种提高CO电还原效率以及减少金属用量的有效策略。然而，需要很大的电势来克服能量势垒以提高CO的选择性。本文描述了负载在高Ce浓度的CeO纳米片（NSs）上的8.7 wt%金纳米颗粒（NPs）如何有效地降低CO电还原的过电势。在含47.3% Ce的CeO NSs上的3.6 nm金NPs在0.1 m KHCO溶液中于-0.5 V时实现了90.1%的CO法拉第效率。此外，CO电还原活性与Au-CeO NSs上Ce的含量呈现出强相关性，这一点此前从未被报道过。原位表面增强红外吸收光谱表明，高Ce浓度的Au-CeO NSs促进了CO的活化以及COOH的形成。理论计算也表明，性能的提升归因于在高Ce含量的Au-CeO NSs上COOH形成的增强。
