Mesoporous titanium-based organic frameworks for highly efficient room-temperature oxidative desulfurization using diluted H2O2

A novel Ti-BTC with a mesoporous structure and uniformly dispersed Ti-OH sites was successfully synthesized. • Ti-BTC exhibits outstanding ODS activity; 99.5% of sulfur (1000 ppm) can be oxidized at 40 °C within 20 min. • The ODS activity of Ti-BTC at 40 °C reaches 52.4 mmol h −1 g −1 , exceeding that of most previously reported Ti-MOFs. • DFT results reveal that OH anchored on Ti sites react with H 2 O 2 to form Ti-OOH species that dominate ODS efficiency. • The mesoporous architecture enhances the accessibility of sulfur to Ti-OOH active sites and promotes rapid mass transfer. Desulfurization represents a pivotal process to produce ultraclean fuels, yet the design and fabrication of advanced materials to enhance desulfurization efficiency continues to pose significant challenges. Herein, a novel mesoporous titanium-based organic frameworks (Ti-BTC) was successfully synthesized via a solvothermal route. The optimized Ti-BTC exhibits outstanding oxidative desulfurization (ODS) performance, enabling the complete oxidation of various sulfur-containing compounds (1000 ppm sulfur) into the corresponding sulfones at 30 °C within 14 min or at 50 °C within 3 min with H 2 O 2 /sulfur (O/S) molar ratio of 5. Notably, even when molar ratio of O/S is reduced to 2.5, 99.5% of sulfur species are oxidized at 40 °C within 20 min. The ODS activity of Ti-BTC at 40 °C attains 52.4 mmol h −1 g −1 , surpassing most previously reported Ti-containing organic materials. Density functional theory calculation and comprehensive characterization results demonstrate that Ti-OH group anchored on vacancy Ti sites readily react with H 2 O 2 to generate peroxo-titanium intermediate, which efficiently oxidize pre-adsorbed sulfur and thus determine the overall ODS efficiency. Additionally, the mesoporous structure of Ti-BTC improves the accessibility of sulfur to in-situ-generated Ti-OOH species and facilitates rapid mass transfer, which synergistically enhances the catalytic performance. Download: Download high-res image (496KB) Download: Download full-size image