Facet-Defined Dilute Metal Alloy Nanorods for Efficient Electroreduction of CO₂ to n-Propanol

Electroreduction of CO₂ into liquid fuels is a compelling strategy for storing intermittent renewable energy. Here, we introduce a family of facet-defined dilute copper alloy nanocrystals as catalysts to improve the electrosynthesis of n-propanol from CO₂ and H₂O. We show that substituting a dilute amount of weak-CO-binding metals into the Cu(100) surface improves CO₂-to-n-propanol activity and selectivity by modifying the electronic structure of catalysts to facilitate C₁-C₂ coupling while preserving the (100)-like 4-fold Cu ensembles which favor C₁-C₁ coupling. With the Au0.02Cu0.98 champion catalyst, we achieve an n-propanol Faradaic efficiency of 18.2 ± 0.3% at a low potential of -0.41 V versus the reversible hydrogen electrode and a peak production rate of 16.6 mA·cm⁻². This study demonstrates that shape-controlled dilute-metal-alloy nanocrystals represent a new frontier in electrocatalyst design, and precise control of the host and minority metal distributions is crucial for elucidating structure-composition-property relationships and attaining superior catalytic performance.