A highly effective liquid phase system for hydrogenation of CO₂ to methanol using a heterogeneous Cu/ZnO/Al₂O₃ catalyst under batch conditions was developed. Among the screened solvents, glycols were found to have a marked promoting effect on methanol formation at a relatively low temperature range of 170–200 °C using molecular H₂. Relative to the solventless system, ethylene glycol enhanced the CO₂ conversion values by up to 120% which is close to the calculated equilibrium limit. CH₃OH yields of up to 90% were achieved. The catalyst was remarkably stable and recyclable over multiple hydrogenation cycles. Furthermore, CO₂ captured by alkali hydroxides as well as amines were successfully hydrogenated to CH₃OH with the Cu/ZnO/Al₂O₃ catalyst for the first time with >90% yields. The catalytic process and the plausible reaction pathways were evaluated by control experiments, which suggest that the hydrogenation in the presence of an alcohol proceeds through the formation of formate ester as an intermediate. Finally, the integration of direct air capture (DAC) and hydrogenation of CO₂ was demonstrated efficiently as a novel methanol synthesis process using the combination of heterogeneous catalysis and air as a renewable carbon source. Such scalable processes have considerable potential for synthesis of renewable methanol in an efficient and relatively cost-effective approach.

开发了在间歇条件下使用非均相Cu/ZnO/Al ₂ O ₃催化剂将CO ₂加氢为甲醇的高效液相系统。在筛选出的溶剂中，发现乙二醇在 170-200 °C 的相对较低温度范围内使用分子 H ₂对甲醇的形成具有显着的促进作用。相对于无溶剂系统，乙二醇将 CO ₂转化率提高了 120%，接近计算的平衡极限。实现了高达 90% 的CH ₃ OH 产率。该催化剂非常稳定，可在多个加氢循环中回收利用。此外，CO ₂被碱金属氢氧化物和胺捕获的 NH4 被Cu/ZnO/Al ₂ O ₃催化剂成功氢化成 CH ₃ OH，产率 > 90%。通过对照实验评估了催化过程和可能的反应途径，这表明在醇存在下的氢化通过形成作为中间体的甲酸酯进行。最后，直接空气捕获 (DAC) 和 CO ₂加氢的集成使用多相催化和空气作为可再生碳源的组合，作为一种新型甲醇合成工艺被有效地证明。这种可扩展的工艺在以高效且相对具有成本效益的方法合成可再生甲醇方面具有相当大的潜力。