Synthesis of Cu-ZnO-based catalysts via surfactant-assisted co-precipitation for CO ₂ hydrogenation to methanol

In the context of global climate change, CO2 hydrogenation to methanol has attracted considerable interest due to its environmental and economic benefits. However, catalysts prepared via conventional co-precipitation often suffer from inadequate dispersion of active components and poor pore structure control. To address these limitations, this study employed a surfactant-assisted co-precipitation method to investigate the influence of cetyltrimethylammonium bromide (CTAB) on Cu-ZnO-X (X = CeO2, ZrO2, Y2O3) catalysts. Characterization by N2 adsorption-desorption, XRD, H2-TPR, and CO2-TPD revealed that CTAB incorporation effectively inhibits the sintering of Cu species, improves active-site dispersion, increases specific surface area and pore volume, and promotes the formation of medium-strength basic sites. These combined effects substantially enhance the catalytic performance. The extent of catalytic enhancement was found to be closely associated with the synergistic effects of CTAB modulation and carrier properties. Specifically, for the Cu-ZnO-CeO2 catalyst, CTAB achieved the highest methanol selectivity by markedly increasing the hydrogen adsorption capacity; for the Cu-ZnO-Y2O3 catalyst, CTAB demonstrated optimal CO2 conversion and methanol spatiotemporal yield through enhanced exposure of alkaline sites and improved metal dispersion; while for the Cu-ZnO-ZrO2 catalyst, CTAB significantly enhanced methanol selectivity by modulating the surface acidity and alkalinity.