From CO to DME: Enhancement through Heteropoly Acids from a Catalyst Screening and Stability Study.

The direct synthesis of dimethyl ether (DME) CO hydrogenation in a single step was studied using an improved class of bifunctional catalysts in a fixed bed reactor ( : 210-270 °C; 40 bar; gas hourly space velocity (GHSV) 19,800 NL kg h; ratio CO/H/N 3:9:2). The competitive bifunctional catalysts tested in here consist of a surface-basic copper/zinc oxide/zirconia (CZZ) methanol-producing part and a variable surface-acidic methanol dehydration part and were tested in overall 45 combinations. As dehydration catalysts, zeolites (ferrierite and β-zeolite), alumina, or zirconia were tested alone as well as with a coating of Keggin-type heteropoly acids (HPAs), i.