Zhang Ziyi, Dong Yutao, Carlos Corey, Wang Xudong
Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States.
ACS Nano. 2023 Sep 12;17(17):17180-17189. doi: 10.1021/acsnano.3c05014. Epub 2023 Sep 1.
The ethanol oxidation reaction (EOR) is an economical pathway in many electrochemical systems for clean energy, such as ethanol fuel cells and the anodic reaction in hydrogen generation. Noble metals, such as platinum, are benchmark catalysts for EOR owing to their superb electrochemical capability. To improve sustainability and product selectivity, nickel (Ni)-based electrocatalysts are considered promising alternatives to noble-metal EOR. Although Ni-based electrocatalysts are relieved from intermediate poisoning, their performances are largely limited by their relatively high onset potential. Therefore, the EOR usually competes with the oxygen evolution reaction (OER) at working potentials, resulting in a low EOR efficiency. Here, we demonstrate a strategy to modify the surface ligands on ultrathin Ni(OH) nanosheets, which substantially improved their catalytic properties for the alkaline EOR. Chemisorbed octadecylamine ligands could create an alcoholophilic layer at the nanosheet surface to promote alcohol diffusion and adsorption, resulting in outstanding EOR activity and selectivity over the OER at higher potential. These non-noble-metal-based 2D electrocatalysts and surface ligand engineering showcase a promising strategy for achieving high-efficiency electrocatalysis of EOR in many practical electrochemical processes.
乙醇氧化反应（EOR）在许多用于清洁能源的电化学系统中是一条经济的途径，例如乙醇燃料电池以及制氢过程中的阳极反应。诸如铂等贵金属，因其卓越的电化学性能，是EOR的基准催化剂。为了提高可持续性和产物选择性，镍（Ni）基电催化剂被认为是贵金属EOR的有前景的替代物。尽管Ni基电催化剂可避免中间产物中毒，但其性能在很大程度上受其相对较高的起始电位限制。因此，EOR在工作电位下通常会与析氧反应（OER）竞争，导致EOR效率较低。在此，我们展示了一种修饰超薄Ni(OH)纳米片表面配体的策略，这极大地改善了它们对碱性EOR的催化性能。化学吸附的十八烷基胺配体可在纳米片表面形成亲醇层，以促进醇的扩散和吸附，从而在较高电位下对OER表现出出色的EOR活性和选择性。这些基于非贵金属的二维电催化剂和表面配体工程展示了一种在许多实际电化学过程中实现高效EOR电催化的有前景的策略。
