Modification of cobalt doped mesoporous sieve by grafting N,N-dihydroxypyromellitimide to enhance desulfurization catalyst stability

Elaborate design of high stability catalytic active site is of great concern for the development of advanced organic–inorganic composite catalysts. Herein, cobalt-doped mesoporous molecular sieve grafted with N,N-dihydroxypyromellitimide catalyst (Co-SBA-15-NDHPI) is developed for the catalytic oxidative desulfurization (ODS) in diesel fuels. The close integration of organic active components and porous supports strengthens the synergistic catalytic effect, resulting enhancement of selective oxidation of sulfides to sulfone derivatives. In detail, N,N-dihydroxypyromellitimide is bonded to a Co-based mesoporous molecular sieve by 3-glycidyloxypropyltrimethoxysilane as the coupling agent allowing exclusive retention of NHPI, which serve as the active sites that result in boosted catalytic ODS performance. Meanwhile, taking advantage of strong chemical anchoring strategies, the Co-SBA-15-NDHPI catalyst exhibits the highest stability compared to other NHPI-containing desulfurization catalysts. This work opens the way for the development of a more stable organic–inorganic hybrid desulfurization catalyst.