School of Physics and Electronics, Hunan University, Changsha, 410082, P. R. China.
ARC Centre of Excellence for Electromaterials Science, Intelligent Polymer Research Institute, University of Wollongong, New South Wales, 2522, Australia.
Phys Chem Chem Phys. 2019 Oct 14;21(38):21341-21348. doi: 10.1039/c9cp03692j. Epub 2019 Sep 18.
Electrochemically converting CO into fuels and chemicals is an appealing strategy to create energy rich products. The highly demanded product ethylene has been preferably produced on Cu-based catalysts with abundant exposed Cu(100) facets. However, the performance is still limited by the large energy barrier for the C-C dimerization. Here, to lower the energy barrier, we tailor the electronic structure of Cu(100) by doping a series of transition metals using the density functional theory (DFT) method. The zinc-doped Cu(100) surface has shown a superior catalytic performance. Mechanistic study further reveals that doping with Zn alters the electronic structure around Cu, adjusts the atomic arrangement in the active sites and makes the catalyst surface electronegative, which is conducive to the activation of acidic molecular CO and the reduction of the energy barrier for C-C dimerization. This work reveals that the doping of Cu with transition metals has great potential in promoting the electrochemical CO-to-CH conversion. This work also provides deep insights into the formation mechanisms of CH, thus guiding the design of Cu-based bimetallic catalysts for its effective production.
电化学将 CO 转化为燃料和化学品是创造富含能量产品的一种有吸引力的策略。高需求的产品乙烯优选在具有丰富暴露的 Cu(100)面的铜基催化剂上生产。然而,其性能仍然受到 C-C 二聚化的大能垒的限制。在这里,为了降低能垒,我们使用密度泛函理论 (DFT) 方法通过掺杂一系列过渡金属来调整 Cu(100)的电子结构。锌掺杂的 Cu(100)表面表现出优异的催化性能。机理研究进一步表明,锌掺杂改变了 Cu 周围的电子结构,调整了活性位的原子排列,并使催化剂表面带负电,这有利于酸性分子 CO 的活化和 C-C 二聚化能垒的降低。这项工作表明,过渡金属掺杂 Cu 在促进电化学 CO 到 CH 的转化方面具有巨大潜力。这项工作还深入了解了 CH 的形成机制,从而指导了用于其有效生产的 Cu 基双金属催化剂的设计。