Synergistic Functionalization for Promoting Dinitrogen Electroreduction with High Faradaic Efficiency

Abstract

Electrochemical nitrogen reduction is suffering from the bottleneck of poor activity and low electron selectivity. Herein, we precisely synthesize an efficient electrocatalyst using phosphotungstic acid as a platform to anchor Bi species on the four-fold hollow site and associate with Li species on the three-fold hollow site. The well-designed catalyst shows a significant eNRR performance with an ammonia yield rate of 61 ± 1 μg h-1 mgcat.-1 and a recorded Faradaic efficiency of 85 ± 2% at -0.1 V vs. RHE. Isotopic labeling verifies that N atoms of formed NH4+ originate from N2. In situ experiments and theoretical calculations reveal that the Biδ+ species could promote the effective activation and hydrogenation of dinitrogen molecules at the adjacently unsaturated W active sites, and the incorporated Li species reduce the hydrogen reduction rate in the undesirable water splitting. This synergistic functionalization of Bi and Li species contributes to the high-efficient catalyst.