Metal oxide catalysts for methanol synthesis from carbon dioxide-rich syngas

Abstract

Development of metal oxide catalysts for methanol synthesis from carbon dioxide-rich syngas as a function of catalyst preparation process has been carried out by using metal doping such as Zr and Pd. Activity of metal oxide catalysts were investigated in terms of catalyst molar ratio, preparation methods, metal-doped content, alcohol solvent, support, salt precursor, carbon dioxide-containing syngas and metal doping. Reactions were performed under low temperature process in a slurry reactor by using alcohols as a catalytic solvent. Molar ratio of Cu/Zn = 1 exhibited the highest activity. At 170 and 200°C, 0.5%wt Zr/Cu/ZnO prepared by co-precipitation method was the most effective catalyst. 0.5%wt Zr-Cu/ZnO prepared by co-precipitation-impregnation method was an effective catalyst for methanol synthesis with carbon dioxide-rich syngas. 0.5%wt Pd-Cu/ZnO also improved catalytic activity especially for long period of reaction time. High hydrogen consumption of Pd-Cu/ZnO catalyst brought in high reducibility to increase activity. The highest total carbon conversion was found by using 2-propanol as reaction medium. ZnO support played a role to promote activity form carbon dioxide hydrogenation. Cu/ZnO formulated from acetate precursor showed high reactivity. Using of Cu/ZnO catalyst for batch methanol synthesis from carbon dioxide-rich containing syngas resulted in decreasing total carbon conversion due to the catalyst deactivation by carbon dioxide and water. Up to 10%carbon dioxide containing syngas, 0.5%wt Zr-Cu/ZnO promoted activity and stability by increasing carbon dioxide hydrogenation and suppressed water formation in the reaction system