Interfacial Electron Regulation of Rh Atomic Layer-Decorated SnO2 Heterostructures for Enhancing Electrocatalytic Nitrogen Reduction.

Abstract

Ammonia (NH3), which serves as a fertilizer supply, is struggling to satisfy the ever-growing population requirements over the world. The electrocatalytic nitrogen reduction to NH3 production is highly desired but shows the extremely poor activity and selectivity of reported electrocatalysts. In this work, we rationally design a novel Rh atomic layer-decorated SnO2 heterostructure catalyst through the interfacial engineering strategy, simultaneously achieving the highest NH3 yield rate (149 μg h-1 mgcat-1) and Faradaic efficiency (11.69%) at -0.35 V vs the reversible hydrogen electrode. This result is superior to the optimum response of previously reported SnO2- or Rh-based catalysts for electrochemical nitrogen reduction. Both X-ray absorption spectra characterization and density functional theory calculations reveal the strong electron interaction between the Rh atomic layer and the SnO2 heterostructure, which effectively regulated the interfacial electron transfer and d-band center. The downshift of the d-band center results in the greatly reduced H adsorption energy and the highly accelerated reaction kinetics for nitrogen reduction. This work endows a new insight into the interfacial electron regulation for weakening H adsorption and further enhancing the electrocatalytic N2 reduction.