Conversion of dimethyl ether to hydrocarbons catalyzed by Pd-loaded *MRE zeolites

The influence of Pd loading on the conversion of dimethyl ether (DME) to hydrocarbons (DTH) was investigated for *MRE-type zeolite catalysts. Catalysts with different Pd loadings were prepared by incipient wetness impregnation and characterized in terms of morphology, composition and acidity. Co-feeding of H$_2$ during DME conversion increased the resistance of the Pd/*MRE catalysts to deactivation, which significantly increased their lifetimes and thus conversion capacities. The product spectra show high olefin contents, comprising light olefins and higher olefins in the C$_5$–C$_{11}$ range, while contents of aromatics are low. H$_2$ co-feeding reduces the formation of cyclic hydrocarbons and increases the formation of n- and iso-alkanes as well as olefins. Higher Pd loadings slightly decrease olefin production but increase paraffin formation, indicating direct hydrogenation of olefins on Pd nanoparticles. The olefin-rich products offer several possibilities for further processing to fuels and chemicals.