Facet-Defined Dilute Metal Alloy Nanorods for Efficient Electroreduction of CO 2 to n -Propanol.

Electroreduction of CO ₂ 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 CO ₂ and H ₂ O. We show that substituting a dilute amount of weak-CO-binding metals into the Cu(100) surface improves CO ₂ -to- n -propanol activity and selectivity by modifying the electronic structure of catalysts to facilitate C ₁ -C ₂ coupling while preserving the (100)-like 4-fold Cu ensembles which favor C ₁ -C ₁ coupling. With the Au _0.02 Cu _0.98 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.