Resolving Active Sites in Cu/ZnO Methanol Synthesis via Coupled Modelling of Surface Reconstruction and Coverage-dependent Kinetics
Year: 2026
Type: preprint
Abstract: Identifying active sites in heterogeneous catalysis is central to fundamental understanding and designing catalysts, yet it becomes challenging when surface structures, adsorbate coverages and reaction kinetics co-evolve under operating conditions. This challenge is exemplified by the enduring controversy over the active site for methanol synthesis over ZnO/Cu catalysts. Here we combine global structure exploration, grand-canonical sampling, a reactive CuZnCHO machine-learning potential and coverage-consistent microkinetics to establish a condition-dependent picture of the active surface. We show that Zn-Cu alloys, ZnO-like overlayers and partially reduced Zn species are not mutually exclusive active-site models, but distinct states within the same dynamic structural landscape. Activity is maximized within an intermediate thermodynamic window, where a Cu-Zn/Cu-Cu bifunctional ensemble forms near a step rim. These findings reconcile seemingly conflicting active-site assignments and establish a general framework for understanding activity in complicated systems. More broadly, our approach provides a paradigm for identifying activity-structure relationships in catalytic systems.
Source: ChemRxiv
Language: English
Subfield: Catalysis
Field: Chemical Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7214239670