Digging high-speed hierarchical pores within zeolite crystals for deep desulfurization

Abstract Environmental sustainability faces critical compromise from refractory sulfur pollutants in fuels, particularly sterically hindered benzothiophenes. Current technologies prove profoundly inadequate as conventional titanium silicalite-1 (C-TS-1) microporous catalysts suffer rapid pore-blocking and deactivation due to restricted molecular diffusion-rendering deep desulfurization an unresolved technological bottleneck. We pioneer a concept of molecular high-speed channels by creating hierarchically ordered macro-mesopores within TS-1 zeolite single crystals (OMMS-TS-1s), where strategically positioned active Ti sites drive unprecedented ultra-deep oxidative desulfurization (ODS). This breakthrough design enables complete molecular permeation with 10-fold enhanced surface permeability versus conventional TS-1 zeolite, effectively eliminating diffusion constraints. Such significant high-speed hierarchical channels effectively reduce diffusion barriers, enabling exceptional catalytic performance for bulky molecule ODS with an apparent rate constant of 4,6-dimethyldibenzothiophene (4,6-DMDBT) oxidation over OMMS-TS-1 being 16 times increase over C-TS-1, and a complete 4,6-DMDBT conversion in 1.5 hours being 8.3 times faster than C-TS-1.