Application of Microimpinging Stream Reactors in the Preparation of CuO/ZnO/Al₂O₃ Catalysts for Methanol Synthesis

Abstract

A microimpinging stream reactor (MISR) at the size of 1 mm was built with a commercial T-junction and steel capillaries for the preparation of CuO/ZnO/Al2O3 catalysts. The coprecipitation of catalyst precursors in MISR was conducted under precisely controlled concentration, pH and volumetric flow rate (VA), followed by the conventional postprecipitation steps. TEM images showed that the coprecipitation in MISR would generate mostly round catalyst particles with a mean size of 8–10 nm; whereas slightly larger and irregular particles were produced in conventional batch route. In addition, the CuO/ZnO/Al2O3 catalysts prepared in MISR possessed larger BET surface area (SBET), specific copper surface area (SCu) and pore volume as well as better Cu/Zn dispersion when compared to those produced in batch route. It was also found that during the preparation of CuO/ZnO/Al2O3 catalysts in MISR, the reactant concentration (Cmn) and volumetric flow rates (VA) had great influences on the structures and properties of the precursors and the final catalysts. The catalytic performance evaluation by CO hydrogenation to methanol showed that both the catalytic activity and selectivity of CuO/ZnO/Al2O3 catalysts prepared in MISR were superior to those produced in batch route.