Tungsten phosphide nanoparticles anchored on ultrathin carbon nanosheets for efficient oxidative desulfurization: Pivotal roles and generation pathways of singlet oxygen

Singlet oxygen (1O2) is an excellent reactive oxygen species for the selective oxidation of organic compounds. Therefore, its application in oxidative desulfurization (ODS) of fuels is theoretically promising, while this has rarely been systematically investigated. Herein, a novel ultrathin carbon nanosheet (CN)-supported tungsten phosphide (WP) catalyst (WP/CN) was devised and employed to activate hydrogen peroxide (H2O2) for the efficient 1O2 generation in ODS. The turnover frequency of WP/CN for the oxidation of dibenzothiophene was as high as 32.7 h−1 at 60 °C, surpassing that of most reported ODS catalysts. More importantly, benefiting from the high selectivity of 1O2, the WP/CN-H2O2 system exhibited exceptional interference resistance and achieved complete ODS of real diesels at a molar ratio of H2O2 to S of 4:1 (the theoretical value is 2:1), outperforming reported ODS systems. The results of experiments and density functional theory calculations demonstrated that the most reasonable reaction pathway for the formation of 1O2 was H2O2→H2O2*→2OH*→O*→2O*→1O2*. The present findings may provide new insights into the development of high-performance and energy-saving ODS processes. [Display omitted] •The WP/CN catalyst can activate H2O2 to selectively produce 1O2.•Complete ODS of real diesels is achieved over WP/CN at a minimal H2O2 usage.•The WP/CN-H2O2 system still removes 99.8 % of DBT even after 16 cycles.•The most reasonable reaction pathway for the 1O2 generation is unveiled.