Polyoxometalate-Based Poly(ionic liquid) as a Precursor for Superhydrophobic Magnetic Carbon Composite Catalysts toward Aerobic Oxidative Desulfurization

The dispersity of heterogeneous catalysts in solid–liquid biphase reactions is of great importance to their catalytic performance. Herein, superhydrophobic magnetic carbon composite catalysts were synthesized by calcination of magnetic polyoxometalate-based poly(ionic liquid). The magnetic poly(ionic liquid) not only served as the carbon and Mo sources and reductant but also made MoOx uniformly disperse on the surface of amorphous carbon. The superhydrophobic catalyst MoOx/MC-600 with a calcining temperature of 600 °C had a superior catalytic activity, and the sulfur removal reached as high as 97.1%. In contrast, the sulfur removal was only 66.6% with the hydrophilic MoOx/MS-600 calcined without the polymer cation. When the reaction was finished, MoOx/MC-600 could be easily separated by a magnet and recycled at least seven times. Additionally, the existence of low-valence Mo and oxygen vacancies would promote the oxidative reaction.