Transient Solid-State Laser Activation of Indium for High-Performance Reduction of CO2 to Formate.

Abstract

Deficiencies in understanding the local environment of active sites and limited synthetic skills challenge the delivery of industrially-relevant current densities with low overpotentials and high selectivity for CO2 reduction. Here, a transient laser induction of metal salts can stimulate extreme conditions and rapid kinetics to produce defect-rich indium nanoparticles (L-In) is reported. Atomic-resolution microscopy and X-ray absorption disclose the highly defective and undercoordinated local environment in L-In. In a flow cell, L-In shows a very small onset overpotential of ≈92mV and delivers a current density of ≈360mA cm-2 with a formate Faradaic efficiency of 98% at a low potential of -0.62V versus RHE. The formation rate of formate reaches up to 6364.4µmol h-1 , which is nearly 39 folds higher than that of commercial In (160.7µmol h-1 ), outperforming most of the previous results that have been reported under KHCO3 environments. Density function theory calculations suggest that the defects facilitate the formation of *OCHO intermediate and stabilize the *HCOOH while inhibiting hydrogen adsorption. This study suggests that transient solid-state laser induction provides a facile and cost-effective approach to form ligand-free and defect-rich materials with tailored activities.