Solvothermal Synthesis of Defect-Rich Mixed 1T-2H MoS₂ Nanoflowers for Enhanced Hydrodesulfurization

Abstract

Hydrodesulfurization (HDS) is one of the most efficient methods to remove harmful sulfur from oil to produce clean hydrocarbons. Molybdenum sulfide (MoS2) has been used extensively for HDS for several decades, which can be further improved toward more effective catalysts due to its distinctive phase-engineering nature. Here, 1T-2H mixed-phase MoS2 nanoflowers with tunable defects have been synthesized and used in the HDS reaction. A facile solvothermal method involving water, ethanol, and glycerin has been developed for generating stable mixed 1T-2H MoS2 in which the vacancies of both S and Mo have been produced. Detailed characterizations based on transmission electron microscopy, X-ray photoelectron spectra, Raman, and electron paramagnetic resonance show that the 1T/2H ratio and vacancies of MoS2 have been effectively tuned by changing the composition of solvothermal solvent. Temperature-programmed reduction results show greatly affected H2 adsorption behavior of MoS2 by engineering of the phases and defects. In the HDS of dibenzothiophene, stable defect-rich mixed 1T-2H MoS2 with high activity and high hydrogenation selectivity was obtained via the accurately controlled solvothermal environment of water, ethanol, and glycerin. The used catalyst still maintains high performance, which is attributed to the retained mixed 1T-2H phases and the dual defects in the harsh reaction environment.