Amide-assisted synthesis of TS-1 zeolites with active Ti(OH2)2(OH)2(OSi)2 sites toward efficient oxidative desulfurization

Aiming to promote the activity of TS-1 zeolite in catalytic oxidative desulfurization (ODS), a general amide-assisted strategy was proposed to synthesize hierarchical TS-1 zeolite with rich and homogeneously distributed Ti(OH 2 ) 2 (OH) 2 (OSi) 2 species. Strong interactions between acrylamide (AM) and Si/Ti as well as self-polymerization of AM in synthetic gels change the zeolite formation process, thus to effectively construct Ti(OH 2 ) 2 (OH) 2 (OSi) 2 , promote Ti evenly distribution and form micro-mesopore structure. The activity of Ti(OH 2 ) 2 (OH) 2 (OSi) 2 was evaluated by ODS of refractory sulfur-containing compounds. The advantages of Ti(OH 2 ) 2 (OH) 2 (OSi) 2 over TiO 4 in substrate adsorption and reactive intermediate formation for ODS were further proved by theoretical calculations. By adjusting AM amount to optimize the Ti(OH 2 ) 2 (OH) 2 (OSi) 2 content and distribution, the obtained catalyst achieves 134.8 h -1 of turnover frequency and 100 % DBT removal at ten minutes, and maintains > 92 % removal after seven cycles at 333 K. This facile active-site construction strategy is promising to be extended to other heteroatom-containing zeolite catalysts.