Computational Screening Single-Atom Catalysts Supported on g-CN for N₂ Reduction: High Activity and Selectivity

Abstract

It remains a great challenge to design efficient electrocatalysts for nitrogen reduction reaction (NRR) with high activity and high selectivity. Herein, density functional theory calculations were performed to examine the feasibility of a single transition metal (TM, from Sc to Au) atom supported on a novel graphitic carbon nitride (g-CN) for NRR. It was demonstrated that TM atoms could be anchored on g-CN. With the "acceptance−donation" interaction, the activation of a N 2 molecule was favorably achieved on TM/g-CN. Particularly, five candidates (Nb, Mo, Ta, W, and Re/g-CN) were picked out benefitting from their high NRR activity (limiting potentials of −0.42, −0.39, −0.35, −0.29, and −0.39 V, respectively) and high selectivity (faradic efficiencies of 100, 100, 100, 94, and 69%, respectively). Multiple-level descriptors (ΔG *N , ICOHP, and φ) shed light on the origin of NRR activity from the view of energy, electronic structure, and basic characteristics. The kinetic stability was validated to ensure the feasibility in real experimental conditions. This work broadens the understanding of single-atom catalysts for N 2 fixation and contributes to the discovery of effective NRR electrocatalysts.

A durable and pH-universal self-standing MoC–Mo2C heterojunction electrode for efficient hydrogen evolution reaction

“…Γ k -point was adopted for reciprocal space integration. The adsorption energy E ads of H atom on the substrates was defined by 49 , 50 where , , and denote the total energy of the H atom adsorbed on the substrate, the MoC-Mo 2 C heterojunction interface, and hydrogen molecule, respectively.…”

Coordination environments tune the activity of oxygen catalysis on single atom catalysts: A computational study

“…In addition, the projected crystal orbital Hamilton population (pCOHP) analysis was carried out to quantify the strength of TM-O bond after * OOH, * O, and * OH adsorption using the LOBSTER program [48,49], and the VASPsol program was performed to calculate the polarizable implicit solvent models under the water conditions [50,51]. To evaluate the relative stability of the TM-N 3 -C and TM-N 4 -C, ab initio molecular dynamics (AIMD) simulations were carried out for 5 ps under different temperatures (300, 400, 500, 600, and 700 K) [52,53], the formation energy E f and binding energy E b were calculated with the following definition…”

Metal-free C5N2 doped with a boron atom as an efficient electrocatalyst for the nitrogen reduction reaction

“…To evaluate the potential of the B int -doped C 5 N 2 as the electrocatalyst for the conversion of activated N 2 to NH 3 , we investigated the subsequent NRR steps through three possible pathways, [52][53][54][55][56] including the distal, alternating, and enzymatic mechanisms, in which six consecutive hydrogenation and reduction processes are involved (Scheme 1). The computed free energy diagrams for the NRR on B-doped C 5 N 2 along the three pathways are shown in Fig.…”