Proposing Explainable Descriptors Towards Enhanced N2 Reduction Performance on the Two-Dimensional Bismuthine Nanosheets Modified by P-block Element-based Electrocatalysts

Abstract

P-block element-based electrocatalysts that feature tunable electronic structure to achieve exceptional N2 activation and proton suppression have garnered extensive interests in the electrochemical N2 reduction reaction (NRR). Albeit various reaction mechanisms were proposed to understand and optimize the NRR performance, the method to effectively design and rapidly screen potential candidates was still elusive. Herein, a couple of explicit and interpretable descriptors on the entire p-block element-based electrocatalysts are put forward to predict NRR activity and selectivity via high-throughput theoretical simulations and symbolic regression algorithm, taking two-dimensional (2D) bismuthine doped and adsorbed by p-block elements as an example. The descriptor is merely composed by inherent atomic properties (p orbital electron number, electron affinity, electronegativity, and atomic radius, etc.) combining with algebraic operators, independent on the intricated DFT calculations. Multi-task regression results demonstrate that the doped and adsorbed bismuthine system possess the same descriptor, namely, doped descriptor can primely forecast the NRR performance of adsorbed system, vice versa. Five potential candidates (5/40) with outstanding NRR activity, selectivity and stability are screened. C-doped and Si-doped bismuthine possess the less negative limiting potential of NRR [UL(NRR)] with 0.46 and 0.68 V and positive [UL(NRR)UL(HER)] value of 1.15 and 0.13 V, respectively, superior to the majority of reported p-block element-based electrocatalyst, which are expected to be verified by the experimental research. This work offers a feasible solution for developing promising NRR electrocatalysts and potentially other electrochemical reactions on the basis of explainable descriptor using geometric information and intrinsic atomic quantities.