MCM-41 molecular sieve was synthesized by liquid crystal templating and modified by incipient wetness impregnation with different Ca/P ratios. The solids were characterized by XRD, XRF, N2 physisorption and NH3/CO2-TPD. The impregnation of Ca/P considerably increased the acid and basic character of MCM-41 materials, which were subsequently tested as catalysts in the mechanochemical oxidation of diphenyl sulfide, showing good selectivity (ca. 62 and 76%) for the selective production of diphenyl sulfoxide. © 2020 Elsevier Inc.