UiO-66-Supported Phosphotungstic Acid with Dual-Active Sites for Extraction Oxidation Desulfurization of Simulated Fuel at Room Temperature

Extraction oxidation desulfurization technology represents a crucial complementary approach to hydrodesulfurization with its effectiveness fundamentally dependent on the performance of the oxidation desulfurization catalyst. A dual-active-site catalyst, based on phosphotungstic acid (HPW) supported on defect-engineered UiO-66, was developed for extraction oxidative desulfurization of diesel. The defect UiO-66 support was fabricated via a grinding method, and glycine (Gly) was subsequently introduced as a molecular bridge to achieve uniform and stable immobilization of HPW within the metal–organic framework. The obtained catalyst was employed in an ODS process of model diesel (n-octane with 1000 ppmS DBT) at room temperature, where H2O2 served as the oxidant and acetonitrile as the extractant. The results revealed that the Zr active sites in UiO-66 can effectively decompose H2O2 into reactive oxygen radicals at room temperature; subsequently such oxygen radicals combine with the W active site in HPW to form highly oxidizing tungsten peroxide species. By optimization of Zr/W ratios, this synergistic effect endowed the UiO-GlyPW composite with exceptional catalytic performance, enabling complete desulfurization of a model oil containing 1000 ppm sulfur within 10 min at room temperature under the conditions of an O/S molar ratio of 5, a catalyst dosage of 3.0 wt %, and an oil-to-extractant ratio of 1.This work provides fundamental insights into the rational design of dual-active-site catalysts for efficient ODS processes under ambient conditions.