Applied Catalysis A: General, Vol.557, 99-107, 2018
Bifunctional catalysts based on colloidal Cu/Zn nanoparticles for the direct conversion of synthesis gas to dimethyl ether and hydrocarbons
Hybrid catalysts were prepared using well-defined, colloidal Cu/Zn-based nanoparticles as building units. The nanoparticles were immobilized on acidic supports (i.e., gamma-Al2O3, HZSM-5, and HY) to yield a series of bifunctional catalysts with a close proximity of active sites for both methanol synthesis and its further conversion to dimethyl ether (DME) or hydrocarbons (HCs). By this model kit principle, a high comparability of the bifunctional catalysts was ensured. The catalysts were characterized in depth regarding their structure and catalytic performance in the conversion of CO-rich synthesis gas. In situ XAS studies demonstrated the formation of the active phase under reducing conditions. The present study revealed important material parameters to control activity and selectivity of the bifunctional catalysts either towards DME or liquefied petroleum gas (LPG) products in the direct conversion of simulated biomass-derived synthesis gas. In particular, Cu loading, pore structure and Si:Al ratio were investigated.