Suppressing Ethylene Peroxidation via Introduction of Trace Amount of K ⁺ : A Strategy for Low-Cost and Highly Efficient MoVNbTeO x in Oxidative Dehydrogenation of Ethane

High Resolution Image Download MS PowerPoint Slide MoVNbTeO x, one of the most promising catalysts for the oxidative dehydrogenation of ethane (ODHE) process, is conventionally synthesized from metal salt solutions, which limits its application due to the high cost of precursors. In this work, we first improved the synthetic pathway of MoVNbTeO x by using metal oxides as cheap precursors and subsequently applied aqueous ammonia to treat the catalyst sample, which resulted in a fractured morphology and reduced particle size. On this basis, we found out that as the alkaline solution varied, catalytic performance correlates closely with the surface acidity of MoVNbTeO x . By modulating acidity via impregnation with a trace amount of K 2 CO 3, ethylene peroxidation can be effectively suppressed by a 15% decrease in the ratio of ethylene peroxidation rate to primary reaction rate. Compared with the conventional MoVNbTeO x synthesized from salt solutions, this work retained the advantages of metal-oxide-synthesized MoVNbTeO x in terms of activity and cost, while substantially improving the ethylene selectivity. By using this low-cost MoVNbTeO x catalyst, ODHE process can be operated at 54% ethane conversion with 87% ethylene selectivity and a space–time yield reaching 1.42 kg C2H4 ·kg cat –1 ·h –1, demonstrating a viable synthesis route for the potential application of industrial catalysts.