Subsurface oxide plays a critical role in CO2 activation by Cu(111) surfaces to form chemisorbed CO2, the first step in reduction of CO2
Subsurface oxide plays a critical role in CO2 activation by Cu(111) surfaces to form chemisorbed CO2, the first step in reduction of CO2
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DOI：
10.1073/pnas.1701405114
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发表时间：
2017-06-27
影响因子：
11.1
通讯作者：
Crumlin, Ethan J.
中科院分区：
文献类型：
--
作者：
Favaro, Marco;Xiao, Hai;Crumlin, Ethan J.
国家的一个优先事项是将二氧化碳转化为高价值的化学产品，如液体燃料。由于目前的电催化剂是不够的，我们的目标是发现新的催化剂，通过获得一个详细的了解CO2电还原铜表面，最好的电流催化剂的初始步骤。使用环境压力X射线光电子能谱解释与量子力学预测的结构和自由能，我们表明，薄亚氧化物结构的存在下的铜表面是必不可少的结合CO2在物理吸附配置在298 K，我们发现，这种低价氧化物是必不可少的转化为化学吸附的CO2在水的存在下，作为第一步向CO2还原产物例如甲酸盐和CO。这种最佳的低价氧化物导致中性和带电的铜表面位点，为如何设计改进的二氧化碳还原催化剂提供了新的见解。
A national priority is to convert CO2 into high-value chemical products such as liquid fuels. Because current electrocatalysts are not adequate, we aim to discover new catalysts by obtaining a detailed understanding of the initial steps of CO2 electroreduction on copper surfaces, the best current catalysts. Using ambient pressure X-ray photoelectron spectroscopy interpreted with quantum mechanical prediction of the structures and free energies, we show that the presence of a thin suboxide structure below the copper surface is essential to bind the CO2 in the physisorbed configuration at 298 K, and we show that this suboxide is essential for converting to the chemisorbed CO2 in the presence of water as the first step toward CO2 reduction products such as formate and CO. This optimum suboxide leads to both neutral and charged Cu surface sites, providing fresh insights into how to design improved carbon dioxide reduction catalysts.