Wu Fan, Zhan Shaoqi, Yang Li, Zhuo Zhiwen, Wang Xijun, Li Xiyu, Luo Yi, Jiang Jun
Hefei National Laboratory for Physical Sciences at the Microscale, Collaborative Innovation Center of Chemistry for Energy Materials, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China.
Department of Chemistry, University of California, Riverside, California 92521, United States.
J Phys Chem Lett. 2021 Mar 11;12(9):2252-2258. doi: 10.1021/acs.jpclett.1c00267. Epub 2021 Feb 26.
A major bottleneck of large-scale water splitting for hydrogen production is the lack of catalysts for the oxygen evolution reaction (OER) with low cost and high efficiency. In this work, we proposed an electrocatalyst of a curved carbon nanocone embedded with two TMN active sites (TM = transition metal) and used first-principles calculations to investigate their OER mechanisms and catalytic activities. In the particular spatial confinement of a curved nanocone, we found that the distance between intermediates adsorbed on two active sites is shorter than the distance between these two active sites. This finding can be used to enhance OER activity by distance-dependent interaction between intermediates through two different mechanisms. The first mechanism in which an O molecule is generated from two neighboring *O intermediates exhibits a linear activity trend, and the lowest overpotential is 0.27 V for the FeN system. In the second mechanism, selective stabilization of the *OOH intermediate is realized, leading to a new scaling relationship (Δ = Δ + 3.04 eV) associated with a modified OER activity volcano (theoretical volcano apex at 0.29 V). The studied mechanisms of the spatial confinement of a carbon nanocone provide a new perspective for designing efficient OER catalysts.
大规模水分解制氢的一个主要瓶颈是缺乏低成本、高效率的析氧反应（OER）催化剂。在这项工作中，我们提出了一种嵌入两个TMN活性位点（TM = 过渡金属）的弯曲碳纳米锥电催化剂，并使用第一性原理计算来研究其OER机制和催化活性。在弯曲纳米锥的特定空间限制中，我们发现吸附在两个活性位点上的中间体之间的距离比这两个活性位点之间的距离短。这一发现可通过中间体之间依赖距离的相互作用，通过两种不同机制来提高OER活性。第一种机制是由两个相邻的O中间体生成一个O分子，呈现出线性活性趋势，对于FeN体系，最低过电位为0.27 V。在第二种机制中，实现了OOH中间体的选择性稳定，导致与修改后的OER活性火山（理论火山顶点为0.29 V）相关的新标度关系（Δ = Δ + 3.04 eV）。所研究的碳纳米锥空间限制机制为设计高效OER催化剂提供了新的视角。
