Mesoporous catalysts based on Keggin-type heteropolyacids supported on MCM-41 and their application in thiophene hydrodesulfurization

A series of tungsten and molybdenum catalysts supported on MCM-41 were prepared using Keggin heteropolyacids (H3PM12O40, M = Mo or W) as active phase sources and compared with their analogues unsupported. The physicochemical characterization was carried out by, small angle and wide angle X-ray diffraction; thermogravimetric analysis/differential scanning calorimetry; ultraviolet–visible diffuse reflectance and Fourier transform infrared spectroscopies; N2 physisorption and potentiometric titration with N-butylamine, for determination, respectively, of the structure; thermal stabilities; integrity of heteropolyacids; textural properties and superficial acidity. The solids were tested in the thiophene hydrodesulfurization reaction at 400 °C, atmospheric pressure and weight hourly space velocity of 0.48 h−1. In this study, it has been demonstrated the importance of supporting heteropolyacids to increase the catalytic activity. Furthermore, it was proved a correlation between surface acidity and calcination temperature with the activity and stability of these catalysts in the hydrodesulfurization reaction.