Heteronuclear Trimetallic MFe<sub>2</sub> and M<sub>2</sub>Fe (M=V, Nb, and Ta) Clusters for Dinitrogen Activation
Ya Ya Wang, Xunlei Ding, Zhi‐Wen Ji, Xiaomeng Huang, Wei Li
Abstract
Abstract Catalysts with heteronuclear metal active sites may have high performance in the nitrogen reduction reaction (NRR), and the in‐depth understanding of the reaction mechanisms is crucial for the design of related catalysts. In this work, the dissociative adsorption of N 2 on heteronuclear trimetallic MFe 2 and M 2 Fe (M=V, Nb, and Ta) clusters was studied with density functional theory calculations. For each cluster, two reaction paths were studied with N 2 initially on M and Fe atoms, respectively. Mayer bond order analysis provides more information on the activation of N−N bonds. M 2 Fe is generally more reactive than MFe 2 . The coordination mode of N 2 on three metal atoms can be end‐on: end‐on: side‐on (EES) for both MFe 2 and M 2 Fe. In addition, a unique end‐on: side‐on: side‐on (ESS) coordination mode was found for M 2 Fe, which leads to a higher degree of N−N bond activation. Nb 2 Fe has the highest reactivity towards N 2 when both the transfer of N 2 and the dissociation of N−N bonds are taken into account, while Ta‐containing clusters have a superior ability to activate the N−N bond. These results indicate that it is possible to improve the performance of iron‐based catalysts by doping with vanadium group metals.