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 g(DME)/Kg(cat)/h), with no coke formation under the adopted experimental conditions (T-R, 280 degrees C; GHSV, 8800NL/Kg(cat)/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. (C) 2016 Elsevier B.V. All rights reserved.