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

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-ZnO_x 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-Zn^{δ +} 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 ZnO_x can facilitate its secondary uniform nucleation and induce a Zn_xAl₂O_y spinel phase and that CO₂ adsorption on metallic Cu⁰ produces an activated Cu_xO 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.