There is an urgent need to develop technologies that use renewable energy to convert waste products such as carbon dioxide into hydrocarbon fuels. Carbon dioxide can be electrochemically reduced to hydrocarbons over copper catalysts, although higher efficiency is required. We have developed oxidized copper catalysts displaying lower overpotentials for carbon dioxide electroreduction and record selectivity towards ethylene (60%) through facile and tunable plasma treatments. Herein we provide insight into the improved performance of these catalysts by combining electrochemical measurements with microscopic and spectroscopic characterization techniques. Operando X-ray absorption spectroscopy and cross-sectional scanning transmission electron microscopy show that copper oxides are surprisingly resistant to reduction and copper(+) species remain on the surface during the reaction. Our results demonstrate that the roughness of oxide-derived copper catalysts plays only a partial role in determining the catalytic performance, while the presence of copper(+) is key for lowering the onset potential and enhancing ethylene selectivity.

Nature Communications 7, Article number: 12123 doi:10.1038/ncomms12123
Received 02 February 2016 Accepted 02 June 2016 Published 30 June 2016

http://www.nature.com/ncomms/2016/160630/ncomms12123/full/ncomms12123.html

发展新技术利用可再生能源变废为宝势在必行，例如将二氧化碳变为碳氢燃料。尽管效率较低，但电化学方法在铜催化剂的帮助下可以将二氧化碳还原为烃类化合物。美国科学家发展了一种利用等离子法处理氧化的铜催化剂在较低的过电势下催化还原二氧化碳。原位X射线吸收谱和横截面扫描电镜表明：反应过程中氧化亚铜并未被完全还原、Cu+仍然在表面。结果表明：氧化物衍生的铜催化剂在催化性能方面仅起到很小的作用，而Cu+离子是降低起始电位和提高乙烯高选择率具有重要作用。（新材料在线）