Ti-containing hierarchical Beta with highly active sites for deep desulfurization of fuels under mild conditions

Abstract

The deep desulfurization of fuels has attracted much attention, due to the stringent demands of environmental regulations. In this work, we report for the first time that Ti-containing hierarchical Beta prepared by a post-synthetic method was utilized as a catalyst for the deep oxidative desulfurization (ODS) of fuels. It was found that the dealumination of Beta before the introduction of Ti species may greatly enhance the ODS activity of Ti-containing hierarchical Beta in the ODS reactions of both dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT). The Ti-containing hierarchical Beta (Ti-B-M-DA) prepared by desilication–dealumination processes exhibited much better ODS activity than that obtained by direct desilication or dealumination. The TOF number over Ti-B-M-DA reached 58.8 h⁻¹ in the ODS of DBT at 333 K and ambient pressure. More importantly, Ti-B-M-DA exhibited highly active catalytic performance in the ODS of 4,6-DMDBT. The TOF number reached 27.1 h⁻¹ under mild conditions, suggesting that it has the potential for application in deep oxidative desulfurization. Such outstanding catalytic performance could be attributed to the presence of highly active sites and rich mesoporosity in Ti-containing hierarchical Beta.