Catalyst Screening and Mechanism Elucidation of Two-Dimensional Transition Metal Coordinated Porphyrin-Analogue Materials for Nitrogen Fixation

This paper reports the construction of a series of two-dimensional (2D) transition metal coordinated porphyrin-analogue catalytic materials and employs a combined strategy of the first-principles calculations and high-throughput screening to systematically investigate their catalytic activity and reaction mechanisms of electrocatalytic nitrogen reduction reaction (NRR). Ninety metal porphyrin-analogue catalysts are obtained by embedding 30 transition metals (3–5d series) into three classes of two-dimensional porphyrin-analogue substrates. High-throughput screening and full reaction pathway search reveal that MoPp-β-H-meso-Diyne, MoPp-meso-H-β-Ph and MoPp-meso-H-β-Py are the optimal catalysts via the distal pathway with onset potentials of −0.21, −0.26 and −0.28 V, respectively. WPp-meso-H-β-Py and RePp-β-H-meso-Diyne also exhibit good catalytic performance with onset potentials of −0.46 and −0.46 V, respectively. All five catalytic materials demonstrate good electronic conductivity and high stability. A volcano-shaped relationship is unveiled between the free energy change of the first protonation step (ΔG *N2 → *N2H) and the onset potential (U onset), which can be utilized to describe the catalytic activity of NRR and guide the design and selection of efficient catalysts.