Facile preparation of polyoxometalate nanoparticles via a solid-state chemical reaction for aerobic oxidative desulfurization catalysis

Polyoxometalate nanoparticles were synthesized via a concise solid-state reaction method by directly grinding silver nitrate and the polyoxometalate (NH4)(5)H6PMo4V8O40 at room temperature without the assistance of a surfactant. The as-prepared Ag-6(NH4)(5)PMo4V8O40 (AgPMo4V8) comprised uniform nanoparticles of 50 nm size, which provided significant catalytic oxidative desulfurization (CODS) performance using O-2, N-2 + O-2 or air as an oxidant. The high efficiency of 100% removal was obtained using AgPMo4V8 nanoparticles as a catalyst in treating model refractory sulfurs. The coexistence of Ag+ and PMo4V8O4011- was the main contribution for this CODS procedure, and the Ag+ species was employed as the electron transfer mediator (ETM) and the PMo4V8O4011- anion was used as the electron donor. The internal electron transfer between Ag+/Ag-0 and V5+/V4+ allowed AgPMo4V8 to mimic oxygenase to release the activation energy of oxygen. AgPMo4V8 nanoparticles also exhibited potential for practical catalytic application in the CODS of diesel and gasoline to produce ultra-clean oils with a S content lower than 10 ppm under mild reaction conditions using a mixture of N-2 and O-2, thus favoring industrial application.

Automated summary

Polyoxometalate nanoparticles were successfully synthesized through a solid-state reaction method without the use of a surfactant, demonstrating excellent catalytic oxidative desulfurization performance for refractory sulfur compounds in diesel and gasoline. The coexistence of Ag+ and PMo4V8O4011- played a key role in the CODS process, with Ag+ acting as the electron transfer mediator and PMo4V8O4011- as the electron donor. AgPMo4V8 nanoparticles showed great potential for industrial application, producing ultra-clean oils with S content below 10 ppm under mild reaction conditions.