Methanol formation from CO₂ and molecular hydrogen on ZnO/Cu catalysts is studied by gradient corrected density functional theory. The catalytically active region is modeled as a minimum size inverse catalyst represented by Zn_XO_Y(H) clusters of different size and a ZnO nano-ribbon on an extended Cu(1 1 1) surface. These systems are chosen as a representative of thermodynamically stable catalyst structures under typical reaction conditions. Comparison to a high level wave function method reveals that density functional theory systematically underestimates reaction barriers, but nevertheless conserves their energetic ordering. In contrast to other metal-supported oxides like ceria and zirconia, the reaction proceeds through the formation of formate on ZnO_X/Cu, thus avoiding the CO intermediate. The difference between the oxides is attributed to variance in the initial activation of CO₂. The energetics of the formate reaction pathway is insensitive to the exact environment of undercoordinated Zn active sites, which points to a general mechanism for Cu-Zn based catalysts.

利用梯度校正密度泛函理论研究了在ZnO / Cu催化剂上由CO ₂和分子氢形成甲醇的过程。催化活性区域建模为最小尺寸的逆催化剂，该催化剂由不同尺寸的Zn _X O _Y（H）簇和扩展的Cu（1 1 1）表面上的ZnO纳米带表示。选择这些系统作为典型反应条件下热力学稳定催化剂结构的代表。与高水平波函数方法的比较表明，密度泛函理论系统地低估了反应势垒，但仍保留了它们的能量有序。与其他金属负载的氧化物（如二氧化铈和氧化锆）相反，该反应通过在ZnO上形成甲酸盐来进行_X / Cu，因此避免了CO中间体。氧化物之间的差异归因于CO ₂的初始活化中的变化。甲酸反应途径的能量学对未配位的Zn活性位点的确切环境不敏感，这表明Cu-Zn基催化剂的一般机理。