Unraveling the Effect of Tensile Strain on Electrochemical CO2 Reduction

Abstract Introducing tensile strain into copper-based (Cu-based) catalysts is a promising strategy for improving the performance of the electrochemical CO2 reduction reaction (CO2RR). However, isolating the influence of the strain effect remains challenging owing to the convoluted contributions from grain boundaries, ligands, and facets. Herein, we utilize in situ attenuated total reflectance surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS) to isolate the effect of strain on the CO2RR performance and determine the strain–activity correlations by taking advantage of synthesizing colloidal nanoparticles with well-defined structures. Tensile strain is shown to modulate CO2RR performance by tuning the CO binding strength of the Cu-based catalysts. Medium tensile strain leads to moderate CO adsorption, which is beneficial for the formation of multicarbon products. Excessively strong CO adsorption would instead hinder the CO2RR and promote the hydrogen evolution reaction. This work provides experimental evidence for the rational design of high-performance CO2RR catalysts to produce C2+ products via strain engineering.