Metal dimers anchored on boron nitride monolayers with boron divacancy as an effective nitrogen fixation electrocatalyst: A computational study

Abstract

As a fascinating approach for sustainable NH3 production, the electrocatalytic nitrogen reduction reaction (NRR) is still hampered by low Faraday efficiency due to high energy required for inert N N triple bond activation and competitive hydrogen evolution reaction (HER). In this paper, we propose a method to increase the NRR catalytic activity by constructing bimetallic sites on boron nitride (BN) monolayer. In order to approach the efficient NRR region, the metal-based linear-scaling relationship between adsorbed intermediates is broken by synergistic effects between the bimetallic active sites. TiRu-BN was identified as an effective NRR electrocatalyst with low limiting potential (−0.28 V) and superior selectivity after systematic evaluation of the thermal stability, electrochemical stability, activity, and selectivity of 36 homo- and heteronuclear diatomic catalyst candidates. Analysis on the origin of high performance shows the screened high-performance diatomic catalyst is located in the region of moderate linear-scaling relationship breaking of intermediates. Breaking the linear scale relationship to the most significant extend does not imply the most improved catalytic activity. This work not only provides experimentally synthesizable exceptional NRR electrocatalyst candidates, but also provides theoretical guidance for practical application of efficient NRR electrocatalyst.