Catalytic features of CuZnZr–zeolite hybrid systems for the direct CO2-to-DME hydrogenation reaction

The direct hydrogenation of CO2 to dimethyl ether (DME) has been studied in a fixed bed reactor, in presence of supported CuZnZr/zeolite hybrid catalysts. To study the effects of zeolite topology on catalyst performance, two different home-made zeolite structures (i.e., FER and MOR) were used as carriers during gel-oxalate coprecipitation of CuZnZr precursors. The hybrid FER-based catalyst showed a very good activity-selectivity pattern at 5.0 MPa, also exhibiting an interesting DME productivity (STY, 752 gDME/Kgcat/h), with no coke formation under the adopted experimental conditions (TR, 280 °C; GHSV, 8800 NL/Kgcat/h). The presence of well dispersed metal-oxide clusters of the precursors on the 2-D zeolite framework of FER was indicated as a key factor to realize a more efficient mass-transferring of MeOH from CuZnZr sites to zeolite surface, favoring so the formation of DME with higher yields than obtained using MOR as support.