n-Butane Oxidation to Maleic Anhydride: Reaction Mechanism and Kinetics Over VPO Catalyst

An increase in zero carbon footprint awareness leading to addressing the hot issue of global warming has led to steps taken in an attempt to reduce atmospheric carbon emissions. Industrial development during the past centuries has made a major contribution in releasing massive amounts of carbon-based gaseous products into the atmosphere. Among these gases, low-carbon alkanes, such as n-butane, are released from refinery processes. Recent years have witnessed the conversion of n-butane to high-value chemicals, such as maleic anhydride, using vanadium-based catalysts. The catalyst complex comprising vanadium phosphorus oxide is found naturally in approximately 15 different phases that are a function of intrinsic properties such as active sites and catalyst structure. The conversion of n-butane to maleic anhydride is a multistep process that involves n-butane oxidation to maleic anhydride along with undesired byproducts. Hence, a thorough investigation of the reaction mechanism becomes vital. Moreover, with the advent of computational tools such as density functional theory, scientists have been able to predict the performance of the catalyst, while with the aid of Aspen simulation, the process can also be modeled. Later these computational calculations are linked with various kinetic models to evaluate the performance of the catalysts. This review is focused on elaborating all the above-mentioned different aspects.