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

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 ≈92 mV and delivers a current density of ≈360 mA cm^-2 with a formate Faradaic efficiency of 98% at a low potential of -0.62 V versus RHE. The formation rate of formate reaches up to 6364.4 µmol h^-1<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:semantics><mml:mrow><mml:mi>m</mml:mi><mml:msubsup><mml:mi>g</mml:mi><mml:mtext>In</mml:mtext><mml:mrow><mml:mo>-</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:msubsup></mml:mrow><mml:annotation>$mg_{{\rm{In}}}^{--1}$</mml:annotation></mml:semantics></mml:math> , which is nearly 39 folds higher than that of commercial In (160.7 µmol h^-1<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:semantics><mml:mrow><mml:mi>m</mml:mi><mml:msubsup><mml:mi>g</mml:mi><mml:mtext>In</mml:mtext><mml:mrow><mml:mo>-</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:msubsup></mml:mrow><mml:annotation>$mg_{{\rm{In}}}^{--1}$</mml:annotation></mml:semantics></mml:math> ), 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.