Role of preparation parameters on the structure–selectivity properties of MoO3/Al2O3 catalysts for the oxidative dehydrogenation of ethane

Two MoO3/γ-Al2O3 catalysts containing 11% (w/w) MoO3 prepared by equilibrium-deposition-filtration at two different pairs of pH and Mo concentration values (pH=3.9, CMo=1.1×10−3 mol L−1 and pH=6.3, CMo=2.7×10−2 mol L−1) were studied for the ethane oxidative dehydrogenation. The two catalysts demonstrated similar ethane conversions in a temperature range 450–600 °C. Selectivity to ethene was 15% higher for the catalyst prepared at relatively low pH than for the sample prepared at a higher pH. The observed difference in ethylene selectivity was related to the different structural characteristics of the molybdena phase in the two catalysts.