THE CO2 HYDROGENATION TOWARD THE MIXTURE OF METHANOL AND DIMETHYL ETHER - INVESTIGATION OF HYBRID CATALYSTS

Catalytic hydrogenation of carbon dioxide for the simultaneous synthes is of methanol and dimethyl ether (together called oxygenates) over a combination of methanol synthesis and methanol dehydration catalysts h as been studied. Various methanol synthesis and methanol dehydration c atalysts were examined for this reaction. The addition of promoters li ke Ga2O3 and Cr2O3 to Cu/ZnO catalyst gave much more enhanced yield on the formation of oxygenates. From the results, the promotional effect of Cr2O3 has been explained in terms of increase in the intrinsic act ivity of Cu while that of Ga2O3 being increase in the dispersion of Cu . Among the methanol dehydration catalysts examined, the solid acids b earing high population of intermediate-strength acid sites were found to be very effective for the production of oxygenates. HY zeolite whic h contains strong acid sites produce small amount of hydrocarbons as b y-products. However, CuNaY zeolite in which the presence of strong aci d sites are minimum gives very high oxygenates yield without the forma tion of hydrocarbons.