Unravelling the Zn‐Cu Interaction during Activation of a Zn‐promoted Cu/MgO Model Methanol Catalyst

We report on an inverse model Cu/MgO methanol catalyst modified with 5 % zinc oxide at the Cu surface to element-specifically probe interplay of metallic copper and during reductive activation. The structure was unraveled by in situ X-ray diffraction (XRD) absorption spectroscopy (XAS) supported theoretical modelling extended fine near-edge spectra. Temperature-programmed reduction H2 XAS showed that reduced starting 145 °C. With increasing temperature, underwent first a geometrical change its structure, followed reduction. species were identified as alloy sites, which coexisted from 200 °C 340 ZnO surface. At 400 Zn−Cu bulk-alloyed particles formed. According XRD XAS, about half not fully reduced, can be explained lack contact copper. Our experimental results further substantiated density functional theory calculations, verified neighboring atoms more easily. By combining these results, distribution, phase oxidation state Zn estimated for activated this catalyst. This insight into forms basis deeper understanding active sites synthesis.