Methanol synthesis by CO₂ reduction is an important approach for energy storage. Aiming at a reduction of the catalyst mass in technical applications, we have investigated the influence of increasing Au loading on the performance of Au/ZnO in methanol and CO formation from CO₂ reduction. Using the same type of ZnO support, increased Au loading resulted also in a pronounced increase in Au particle size. The Au-mass-normalized reaction rate for methanol formation and TOF decrease with increasing Au loading/particle size, while the selectivity for methanol formation increases. CO adsorption monitored by in situ FTIR revealed a pronounced decrease of the accessible Au surface area during reaction, independent of the Au loading, pointing to a partial encapsulation of the Au nanoparticles by a partly reduced ZnO_x, as described by SMSI effects. Possible reasons responsible for these effects and Au loading/size effects therein are discussed, strategies for future work are outlined.

通过 CO ₂还原合成甲醇是一种重要的储能方法。为了在技术应用中减少催化剂质量，我们研究了增加 Au 负载量对 Au/ZnO 在甲醇中的性能和 CO ₂还原形成 CO 的影响。使用相同类型的 ZnO 载体，增加 Au 负载也会导致 Au 粒径显着增加。甲醇形成和 TOF 的 Au 质量归一化反应速率随着 Au 负载量/粒径的增加而降低，而甲醇形成的选择性增加。原位监测CO吸附FTIR 显示反应期间可及的 Au 表面积显着减少，与 Au 负载无关，这表明 Au 纳米颗粒被部分还原的 ZnO _x部分包封，如 SMSI 效应所述。讨论了造成这些影响的可能原因和 Au 负载/尺寸效应，并概述了未来工作的策略。