Liquid Metal Gallium Promotes the Activity and Stability of the Cu-ZnO Catalyst for CO2 Hydrogenation to Methanol

CO2 hydrogenation to methanol has attracted considerable attention as a promising catalytic route for both reducing CO2 emissions and producing valuable chemical intermediates. Among various catalysts, Cu–ZnO-based systems are the most widely studied; however, their performance remains constrained by limited methanol selectivity and stability, highlighting the need for improved catalytic strategies. In this work, liquid metal gallium (Ga) was incorporated into Cu–ZnO catalysts as an additive for CO2 hydrogenation to methanol. Owing to its high dispersibility and fluidity, Ga helps maintain long-term catalyst stability. We investigated different introduction methods for Ga promoters and found that the physical mixing approach generated the strongest alkaline sites, thereby enhancing CO2 activation and increasing the CO2 conversion to methanol. Moreover, this catalyst effectively suppressed carbon deposition, further improving its stability. These findings offer new insights into the use of liquid metal Ga in CO2 hydrogenation and provide fresh perspectives for the rational design of efficient methanol synthesis catalysts.