The Role of Copper Valence States in CuZnAl Catalysts for CO2-to-Methanol Conversion

• • K modification inhibits CuO reduction, reducing Cu2O active species under reaction conditions, leading to decreased catalytic activity for CO2-to-methanol conversion. • • Increased K loading raises the proportion of Cu0 species, which promotes the RWGS side reaction, suppressing methanol formation. • • CO2-TPD shows K modification covers basic sites, suppressing CO2 adsorption capacity, impacting overall catalytic efficiency. • • In situ IR spectroscopy confirms a HCOO*-mediated pathway for CO2 hydrogenation to methanol over CZA catalysts, providing mechanistic insight for catalyst design.