Dual Nature Cupper-Based Ionic Liquid-Assisted n-Butane Selective Oxidation with a Vanadium Phosphorus Oxide Catalyst

Recently, global warming is proving to be an increasing challenge for the sustainable human survival on planet earth. Worldwide, researchers are putting their efforts into controlling carbon emissions and have set the aim to achieve levels of overall carbon neutrality. Different industrial processes, especially oil refinery processes, release large amounts of low-carbon alkanes as gaseous byproducts directly into the air and pollute clean environments, which is one of the major reasons for sudden climate changes, ocean acidification, loss of biodiversity, and rising sea levels. The conversion of lighter alkanes, especially n-butane, into value-added chemicals can be beneficial for green economies and green environments. Presently, heterogeneous vanadium phosphorus oxide catalysts (VPOs) are considered potential candidates for n-butane selective oxidation toward maleic anhydride (MA). In this research, we developed a VPO catalyst with the assistance of copper-based ionic liquids (Cu-ILs), including [Bmim][OAc]–[Cu(OAc)₂], [Bmim][Cl]–[CuCl], and [Bmim][Cl]–[CuCl₂]. We observed significant improvement in the MA selectivity; meanwhile, the CO_x (CO and CO₂) selectivity was decreased. Compared to the unpromoted catalyst (Blank-VPO), the Cu-IL-promoted catalyst, i.e., [Bmim][Cl]–[CuCl₂]-VPO remarkably increased the MA selectivity (11%) and n-butane conversion (9.2%) and minimized the CO_x selectivity (11%). In addition to this the ratio of CO/CO₂ has been reduced from 2.01 to 1.32. Therefore, this can be a helpful process for achieving carbon neutrality goals. Graphical Abstract: [Figure not available: see fulltext.]