Department of Physics, Ruhr-University Bochum , 44780 Bochum, Germany.
ACS Nano. 2017 May 23;11(5):4825-4831. doi: 10.1021/acsnano.7b01257. Epub 2017 May 1.
Carbon dioxide electroreduction to chemicals and fuels powered by renewable energy sources is considered a promising path to address climate change and energy storage needs. We have developed highly active and selective copper (Cu) nanocube catalysts with tunable Cu(100) facet and oxygen/chlorine ion content by low-pressure plasma pretreatments. These catalysts display lower overpotentials and higher ethylene, ethanol, and n-propanol selectivity, resulting in a maximum Faradaic efficiency (FE) of ∼73% for C and C products. Scanning electron microscopy and energy-dispersive X-ray spectroscopy in combination with quasi-in situ X-ray photoelectron spectroscopy revealed that the catalyst shape, ion content, and ion stability under electrochemical reaction conditions can be systematically tuned through plasma treatments. Our results demonstrate that the presence of oxygen species in surface and subsurface regions of the nanocube catalysts is key for achieving high activity and hydrocarbon/alcohol selectivity, even more important than the presence of Cu(100) facets.
二氧化碳电化学还原为化学物质和燃料，由可再生能源提供动力，被认为是应对气候变化和能源存储需求的一种很有前途的途径。我们通过低压等离子体预处理，开发了具有可调铜(100)面和氧/氯离子含量的高活性和选择性的铜纳米立方催化剂。这些催化剂表现出更低的过电位和更高的乙烯、乙醇和正丙醇选择性，从而使 C 和 C 产物的最大法拉第效率（FE）达到约 73%。扫描电子显微镜和能量色散 X 射线光谱结合准原位 X 射线光电子能谱表明，通过等离子体处理可以系统地调节催化剂的形状、离子含量和离子在电化学反应条件下的稳定性。我们的结果表明，纳米立方催化剂表面和次表面区域存在氧物种对于实现高活性和碳氢化合物/醇选择性至关重要，甚至比存在 Cu(100)面更为重要。
