Lu Zhiyao, Mitra Debanjan, Narayan Sri R, Williams Travis J
Donald P. and Katherine B. Loker Hydrocarbon Institute, Wrigley Institute for Environment and Sustainability, and Department of Chemistry, University of Southern California, Los Angeles, California, 90089-1661, United States.
Polyhedron. 2024 Apr 1;252. doi: 10.1016/j.poly.2024.116880. Epub 2024 Feb 8.
The oxygen evolution reaction (OER) of water splitting is essential to electrochemical energy storage applications. While nickel electrodes are widely available heterogeneous OER catalysts, homogeneous nickel catalysts for OER are underexplored. Here we report two carbene-ligated nickel(II) complexes that are exceptionally robust and efficient homogeneous water oxidation catalysts. Remarkably, these novel nickel complexes can assemble a stable thin film onto a metal electrode through poly-imidazole bridges, making them supported heterogeneous electrochemical catalysts that are resilient to leaching and stripping. Unlike molecular catalysts and nanoparticle catalysts, such electrode-supported metal-complex catalysts for OER are rare and have the potential to inspire new designs. The electrochemical OER with our nickel-carbene catalysts exhibits excellent current densities with high efficiency, low Tafel slope, and useful longevity for a base metal catalyst. Our data show that imidazole carbene ligands stay bonded to the nickel(II) centers throughout the catalysis, which allows the facile oxygen evolution.
水分解的析氧反应（OER）对于电化学储能应用至关重要。虽然镍电极是广泛使用的非均相OER催化剂，但用于OER的均相镍催化剂尚未得到充分研究。在此，我们报道了两种卡宾配位的镍（II）配合物，它们是异常稳定且高效的均相水氧化催化剂。值得注意的是，这些新型镍配合物可以通过聚咪唑桥在金属电极上组装成稳定的薄膜，使其成为抗浸出和剥离的负载型非均相电化学催化剂。与分子催化剂和纳米颗粒催化剂不同，这种用于OER的电极负载金属配合物催化剂很少见，并且有可能激发新的设计。我们的镍 - 卡宾催化剂的电化学OER表现出优异的电流密度，具有高效率、低塔菲尔斜率以及对于贱金属催化剂而言有用的寿命。我们的数据表明，咪唑卡宾配体在整个催化过程中都与镍（II）中心保持键合，这使得析氧过程能够轻松进行。
