High-Performance Bismuth-Doped Nickel Aerogel Electrocatalyst for the Methanol Oxidation Reaction

Low-cost, non-noble-metal electrocatalysts are required for direct methanol fuel cells, but their development has been hindered by limited activity, high onset potential, low conductivity, and poor durability. A surface electronic structure tuning strategy is presented, which involves doping of a foreign oxophilic post-transition metal onto transition metal aerogels to achieve a non-noble-metal aerogel Ni97Bi3 with unprecedented electrocatalytic activity and durability in methanol oxidation. Trace amounts of Bi are atomically dispersed on the surface of the Ni97Bi3 aerogel, which leads to an optimum shift of the d-band center of Ni, large compressive strain of Bi, and greatly increased conductivity of the aerogel. The electrocatalyst is endowed with abundant active sites, efficient electron and mass transfer, resistance to CO poisoning, and outstanding performance in methanol oxidation. This work sheds light on the design of high-performance non-noble-metal electrocatalysts.

直接甲醇燃料电池需要低成本的非贵金属电催化剂，但其发展受到活性有限、起始电位高、导电性低以及耐久性差的阻碍。本文提出了一种表面电子结构调控策略，即通过将一种亲氧的后过渡金属掺杂到过渡金属气凝胶上，以获得一种在甲醇氧化反应中具有前所未有的电催化活性和耐久性的非贵金属气凝胶Ni97Bi3。微量的Bi原子级分散在Ni97Bi3气凝胶表面，这导致Ni的d带中心发生最佳位移、Bi产生较大的压缩应变以及气凝胶的导电性大幅提高。该电催化剂具有丰富的活性位点、高效的电子和质量传递、抗一氧化碳中毒能力以及在甲醇氧化反应中的出色性能。这项工作为高性能非贵金属电催化剂的设计提供了思路。