Unlocking the Activity of Abundant but Inert Cu Facets in Methanol Synthesis via Single-Atom Defects

Abstract High-index facets of Cu are widely recognized as active sites for methanol synthesis, yet their extremely small fraction constrains overall catalytic performance. In this work, combining the methods of DFT calculations and microkinetic modeling, we propose and demonstrate that introducing single-atom defects can effectively activate abundant but inert low-index Cu facets, such as Cu(111) and Cu(100), resulting in increases of more than two orders of magnitude compared to their pristine counterparts. Particularly, defective Cu(111) approaches the activity of the most active Cu(211) facet, owing to the ability of the defect to lower the energy barrier of key steps from HCOO* to H2COOH*. A defect concentration of ∼7.1% is found to maximize overall activity by optimally balancing intrinsic activity and surface stability. Furthermore, we put forward a possible strategy to generate such active defect building on the advanced single-atom catalyst technologies, with Cl, Br, and I identified as effective defect-inducing elements based on both their favorable doping and diffusion energies. Beyond conventional efforts on scarce active step sites, the activation of abundant low-index facets via single-atom defects provides an effective way to boost overall catalytic performance, opening avenues for catalyst design across various reactions.