The viability of catalyzed CO₂ conversion routes strongly depends on improving the catalytic performance and understanding of the process. Herein, we investigate the effect of Ca loading on PdZn/CeO₂ catalysts prepared using the sol–gel chelatization method for CO₂ hydrogenation to methanol. A remarkable improvement in catalyst performance was revealed with the optimum amount of Ca (0.5 wt%) in synergetic cooperation with the PdZn alloy (main active phase for the CO₂ hydrogenation to methanol reaction), compared to the Ca-free counterpart. The following key performance indicators are attained at 230 °C, 20 bar, and 2400 h⁻¹ GHSV for the optimized catalyst: 16 % CO₂ conversion, > 93 % methanol selectivity, and ∼ 124 g/kg_cat/h methanol space–time yield. The overall catalytic performance observed is attributed to the optimum Ce³⁺/Ce⁴⁺ ratio, Ca²⁺ promotion, surface area, pore volume, and basic sites, as revealed by various characterization techniques. Results shown here indicate that the presence of Ca in the vicinity of the PdZn active enhances basicity, creates oxygen vacancies, and phase may have improved the spill-over ability of H₂, consequently favoring CO₂ activation and methanol formation.

_{催化CO 2}转化路线的可行性在很大程度上取决于提高催化性能和对该过程的理解。在此，我们研究了 Ca 负载量对使用溶胶-凝胶螯合法制备的用于 CO ₂加氢制甲醇的PdZn/CeO ₂催化剂的影响。_{与不含 Ca 的对应物相比，在与 PdZn 合金（CO 2}加氢制甲醇反应的主要活性相）协同作用下，Ca 的最佳含量（0.5 wt%）显着改善了催化剂性能。优化催化剂在 230 °C、20 bar 和 2400 h ⁻¹ GHSV下获得以下关键性能指标：16 % CO ₂转化率、> 93% 的甲醇选择性和 ∼ 124 g/kg _cat /h 的甲醇时空产率。观察到的整体催化性能归因于最佳 Ce ³⁺ /Ce ⁴⁺比率、Ca ²⁺促进作用、表面积、孔体积和碱性位点，如各种表征技术所揭示的那样。_{此处显示的结果表明，在 PdZn 活性附近存在 Ca 会增强碱度，产生氧空位，相可能会提高 H 2}的溢出能力，从而有利于 CO 2 活化和甲醇_形成。