Supercritical CO2 Activation Enables an Exceptional Methanol Synthesis Activity Over the Industrial Cu/ZnO/Al2O3 Catalyst

Abstract

The ternary Cu/ZnO/Al2O3 catalyst is widely used in the industry for renewable methanol synthesis. The tenuous trade-off between the strong metal–support interaction (SMSI)-induced Cu–ZnOx interface and the accessible Cu surface strongly affects the activity of the final catalyst. Successes in the control of oxide migration on adsorbate-induced SMSI catalysts have motivated this to develop a supercritical CO2 activation strategy to synchronously perfect the Cu0–O–Znδ+ interface and Cu0–Cu+ surface sites through the manipulation of the adsorbate diffusion kinetics, which involves *OC2H5 and “side-on” fixed CO2 species. This findings illustrate that the adsorbate on ZnOx can facilitate its secondary uniform nucleation and induce a ZnxAl2Oy spinel phase and that CO2 adsorption on metallic Cu0 produces an activated CuxO amorphous shell. Such a structural evolution unlocks a dual-response pathway in methanol synthesis, thus enabling Cu/ZnO/Al2O3 with a twofold increase in catalytic activity. This atomic-level design of active sites and understanding of supercritical CO2-induced structural evolution will guide the future development of high-performance supported metal catalysts.