Electron\nDelocalization\nDisentangles Activity-Selectivity\nTrade-Off of Transition Metal Phosphide Catalysts in Oxidative Desulfurization

Breaking the activity-selectivity\ntrade-off has been\na long-standing\nchallenge in catalysis. Here, we proposed a nanoheterostructure engineering\nstrategy to overcome the trade-off in metal phosphide catalysts for\nthe oxidative desulfurization (ODS) of fuels. Experimental and theoretical\nresults demonstrated that electron delocalization was the key driver\nto simultaneously achieve high activity and high selectivity for the\nmolybdenum phosphide (MoP)/tungsten phosphide (WP) nanoheterostructure\ncatalyst. The electron delocalization not only promoted the catalytic\npathway transition from predominant radicals to singlet oxygens in\nH<sub>2</sub>O<sub>2</sub> activation but also simultaneously optimized\nthe adsorption of reactants and intermediates on Mo and W sites. The\npresence of such dual-enhanced active sites ideally compensated for\nthe loss of activity due to the nonradical catalytic pathway, consequently\ndisentangling the activity-selectivity trade-off. The resulting catalyst\n(MoWP<sub>2</sub>/C) unprecedentedly achieved 100% removal of thiophenic\ncompounds from real diesel at an initial concentration of 2676 ppm\nof sulfur with a high turnover frequency (TOF) of 105.4 h<sup>–1</sup> and a minimal O/S ratio of 4. This work provides fundamental insight\ninto the structure–activity-selectivity relationships of heterogeneous\ncatalysts and may inspire the development of high-performance catalysts\nfor ODS and other catalytic fields.