Promoting Direct CO2 Conversion to DME over Zeolite-based Hybrid Catalysts

The direct hydrogenation of CO2 into dimethyl-ether (DME) has been studied in presence of zeolite-based hybrid catalysts, prepared through gel-oxalate coprecipitation of copper, zinc and zirconium precursors (in an atomic ratio of 60 : 30 : 10 respectively) in a solution containing different home-made zeolites (i.e., Sil-1, MFI, Y, FER, BEA, MOR), for a final CuZnZr/zeolite weight composition of 1:1. All the samples were properly characterized with different techniques for determining the textural, structural and morphological nature of the catalytic surface. N-2 physisorption highlighted a variation both in the specific surface area and in the pore size distribution from the parent zeolites to the hybrid catalyst. TEM analyses disclosed how the pre-formed zeolite architecture affects the distribution of the oxides on the surface, significantly controlling not only the activity-selectivity pattern under the adopted experimental conditions (T-R, 200-260 degrees C; P-R, 30 bar, GHSV: 8.800 NL/kg(cat)/h), but also the catalyst stability during time on-stream.