Multi-twinned gold nanoparticles with tensile surface steps for efficient electrocatalytic CO2 reduction

CO2 reduction reactions (CO2RR) powered by renewable electricity can directly convert CO2 to hydrocarbons and fix the intermittent sustainable energy in portable chemical fuels. It is of great importance to develop advanced catalysts that can boost CO2RR with high activity, selectivity, and efficiency at low overpotentials. Here, we report the solution synthesis using H2O2 to modify the surface structures of gold multi-twinned nanoparticles (AuMPs) and create tensile surface steps. Calculations predicted significantly enhanced CO2 adsorption and boosted CO2RR capabilities with inhibited hydrogen evolution reaction activity for the tensile surface steps with modified electronic structure. The H2O2-treated AuMPs with surface steps and 3.83% tensile lattices showed much higher activity and selectivity at lower overpotentials for CO2RR than pristine gold nanoparticles. The CO-production current density reached about 98 mA cm(-2) with a Faradaic efficiency of 95.7% at -0.30 V versus reversible hydrogen electrode in the flow cell, showing a half-cell energy efficiency as high as similar to 83%. Our strategy represents a rational catalyst design by engineering the surface structures of metal nanoparticles and may find more applicability in future electrocatalysis.

Automated summary

In this study, we modified the surface structures of gold nanoparticles using a solution synthesis method with H2O2, creating tensile surface steps. The modified gold nanoparticles showed significantly enhanced CO2RR activity and selectivity, with higher CO-production current density and Faradaic efficiency at lower overpotentials.