Fractal Dimension of MoP−Al2O3 Catalysts and Their Activity in Hydrodesulfurization of Dibenzothiophene

Alumina-supported molybdenum phosphide catalysts were prepared by temperature-programmed reduction at 823 and 1123 K under a H2 flow. The catalysts were characterized by physicochemical and spectroscopy techniques. Molybdenum and phosphorous concentration, as well as reduction temperature, emerged as two parameters which influence directly on the morphological and structural aspects of MoP particles at the alumina surface. 95Mo NMR evidences the formation of metallic molybdenum and molybdenum phosphide where molybdenum has a metallic character. The fractal dimension of the catalyst was correlated linearly with the performance in the catalysis of hydrodesulfurization of dibenzothiophene.