Department of Materials Science and Engineering , Technion - Israel Institute of Technology , Haifa 3200003 , Israel.
J Chem Theory Comput. 2018 May 8;14(5):2380-2385. doi: 10.1021/acs.jctc.7b01214. Epub 2018 Apr 18.
Understanding catalytic mechanisms is important for discovering better catalysts, particularly for water splitting reactions that are of great interest to the renewable energy field. One of the best performing catalysts for water oxidation is nickel oxyhydroxide (NiOOH). However, only one mechanism has been adopted so far for modeling catalysis of the active plane: β-NiOOH(01̅5). In order to understand how a second reaction mechanism affects catalysis, we perform Density Functional Theory + U (DFT+U) calculations of a second mechanism for water oxidation reaction of NiOOH. Then, we use a Metropolis Monte Carlo algorithm to calculate how many catalytic cycles are completed when two reaction mechanisms are competing. We find that within the Metropolis algorithm, the second mechanism has a higher overpotential and is therefore not active even for large applied biases.
了解催化机制对于发现更好的催化剂非常重要，特别是对于水分解反应，这对可再生能源领域非常重要。对于水氧化反应，表现最好的催化剂之一是镍氢氧化物（NiOOH）。然而，迄今为止，对于活性平面的催化作用，仅采用了一种机制：β-NiOOH(01̅5)。为了了解第二种反应机制如何影响催化作用，我们对 NiOOH 水氧化反应的第二种机制进行了密度泛函理论+U（DFT+U）计算。然后，我们使用 metropolis 蒙特卡罗算法来计算当两种反应机制竞争时完成了多少个催化循环。我们发现，在 metropolis 算法中，第二种机制具有更高的过电势，因此即使施加较大的偏压也不活跃。
