Sarp Kaya - Koc? University Tu?pras? Energy Center (KUTEM), Department of Chemistry, Koc? University, 34450 Istanbul, Turkey; ? orcid.org/0000-0002-2591-5843

Single-atom catalysts (SACs) consist of a low coverage of isolated metal atoms dispersed on a metal substrate, called single-atom alloys (SAAs), or alternatively single metal atoms coordinated to oxygen atoms on an oxide support. We present the synthesis of a new type of Co1Cu SAC centers on a Cu2O(111) support by means of a site-selective atomic layer deposition technique. Isolated metallic Co atoms selectively coordinate to the native oxygen vacancy sites (Cu sites) of the reconstructed Cu2O(111) surface, forming a Co1Cu SAA with no direct Co- Ox bonds. The centers, here referred to as Co1Cu hybrid SACs, are found to stabilize the active Cu+ sites of the low-cost Cu2O catalyst that otherwise is prone to deactivation under reaction conditions. The stability of the Cu2O(111) surface was investigated by synchrotron radiation-based ambient-pressure X-ray photoelectron spectroscopy under reducing CO environment. The structure and reduction reaction are modeled by density functional theory calculations, in good agreement with experimental results.

Automated summary

This study presents the synthesis and characterization of a new type of Co1Cu hybrid single-atom catalyst (SAC) on a Cu2O(111) support. The Co1Cu hybrid SACs are found to stabilize the active sites of the Cu2O catalyst and improve its stability under reaction conditions.