Effect of the fuel on the surface VOx concentration, speciation and physico-chemical characteristics of solution combustion synthesised VOx/MgO catalysts for n-octane activation

VOx/MgO catalysts, synthesised via solution combustion synthesis were developed for ODH of n-octane using urea, citric acid, hydrazine hydrate, oxalyldihydrazide and glycine as fuels. The effect of these fuels on influencing defects, surface VOx concentration, basic properties and redox properties using various analytical methods were studied. Notable differences in surface and bulk characteristics of the vanadates were observed due to the fuel employed, affecting conversion of octane and selectivity to ODH products. Glycine as fuel gave best octene selectivity due to ease of reducibility of the VOx species, medium surface basicity, and relatively high concentration of surface oxygen vacancies. •SCS method was used to synthesise VOx/MgO catalysts using different fuels•The catalysts were used in the oxidative dehydrogenation of n-octane•The catalyst synthesised with glycine as fuel gave the best activity•Surface basicity and vanadium speciation were among the main drivers for activity