Prominence of Fe on Cu/ZnO/ZrO2 catalyst for methanol synthesis from CO2: Material preparation, performance demonstration, and kinetic analysis

Abstract

A sequence of ZnO/ZrO2-supported Fe/Cu catalysts were prepared and tested for methanol synthesis performance from CO2 using a high-pressure flow reactor. The Fe-containing catalysts showed a greater impact on methanol synthesis than the ZnO/ZrO2-supported Cu and Fe/Cu catalysts. The presence of the tetragonal-ZrO2 phase in the support is highly selective towards methanol formation. A catalyst containing 30 wt% Fe showed a uniform distribution of nanospheres and more oxygen vacancies. H2-TPR investigation revealed that the Fe catalyst offered strong interactions between iron oxides and ZrO2 support. At 250 °C and 30 bar, the Fe-incorporated catalyst showed a remarkable performance with 18.7 % CO2 conversion and 53.8 % methanol selectivity. The catalyst showed excellent thermo-chemical stability under time-on-stream conditions. In-situ DRIFTS analysis revealed the formation of formate and CO intermediates during methanol formation. A single-site kinetic model agrees well with the experimental results.