Understanding the Intrinsic Mechanism of High-Performance
Electrocatalytic Nitrogen Fixation by Heterogenization of Homonuclear
Dual Atom Catalyst
Abstract
A heteronuclear dual transition metal atom catalyst is a promising
strategy to solve and relieve the increasing energy and environment
crisis. However, the role of each atom still does not efficiently
differentiate due to the high activity but low detectivity of each
transition metal in the synergistic catalytic process when considering
the influence of heteronuclear induced atomic difference for each
transition metal atom, thus seriously hindering intrinsic mechanism
finding. Herein, we proposed coordinate environment vary induced
heterogenization of homonuclear dual transition metal, which inherits
the advantage of heteronuclear transition metal atom catalyst but also
controls the variable of the two atoms to explore the underlying
mechanism. Based on this proposal, employing density functional theory
study and machine learning, 23 kinds of homonuclear transition metals
are doping in four asymmetric C3N for heterogenization to evaluate the
underlying catalytic mechanism. Our results demonstrate that five
catalysts exhibit excellent catalytic performance with a low limiting
potential of -0.28 to -0.48 V. In the meantime, a new mechanism,
‘capture-charge distribution-recapture-charge redistribution’, is
developed for both side-on and end-on configuration. More importantly,
the pronate site of the first hydrogenation is identified based on this
mechanism. Our work not only initially makes a deep understanding of the
transition dual metal-based heteronuclear catalyst indirectly but also
broadens the development of complicated homonuclear dual atom catalysts
in the future.