Reaction intermediates recognized by in situ FTIR spectroscopy in CO2 hydrogenation over the Cu/ZnO/SPP-zeolite catalyst†

Cu/ZnO nanoparticles embedded in zeolites possess smaller particle sizes than those in the conventional Cu/ZnO/Al₂O₃ catalyst. Therefore, they exhibit a distinctive manner of interaction with the reactants in the catalytic hydrogenation of CO₂ to methanol. The present paper uses in situ FTIR spectroscopy to recognize the introduction and removal of various carbonates, carbonyl, formates and water species adsorbed on the surface of a Cu/ZnO/SPP-zeolite catalyst in reactive flows. Together with other characterization results, such as quasi-in situ XPS, it was revealed that the Cu surfaces have an uneven electronic distribution and that constant carbonate coverage, low water adsorption, and fast consumption of carbonyls and formates are associated with the high conversion frequency of CO₂ over the Cu/ZnO/zeolite material.