Enhanced Methanol Synthesis over Self-Limited ZnO_x Overlayers on Cu Nanoparticles Formed via Gas-Phase Migration...

Supported metal catalysts are widely used for chemical conversion, in which construction of high density metal-oxide or oxide-metal interface is an important means to improve their reaction performance. Here, Cu@ZnO_x encapsulation structure has been in situ constructed through gas-phase migration of Zn species from ZnO particles onto surface of Cu nanoparticles under CO₂ hydrogenation atmosphere at 450 °C. The gas-phase deposition of Zn species onto the Cu surface and growth of ZnO_x overlayer is self-limited under the high temperature and redox gas (CO₂ /H₂ ) conditions. Accordingly, high density ZnO_x -Cu interface sites can be effectively tailored to have an enhanced activity in CO₂ hydrogenation to methanol. This work reveals a new route for the construction of active oxide-metal interface and classic strong metal-support interaction state through gas-phase migration of support species induced by high temperature redox reaction atmosphere.