Mechanochemical preparation of advanced catalytically active bifunctional Pd-containing nanomaterials for aqueous phase hydrogenation

The preparation of supported Pd nanoparticles on porous materials (Al-SBA-15 and Al-MCF) was successfully achieved using a simple, fast and efficient reactive milling (mechanochemical) method. Upon preparation, catalysts were characterized by N-2 physisorption, elemental analysis, transmission electron microscopy (TEM) and X-ray diffraction (XRD). The catalytic activity of different Pd/Al-SBA-15 and Pd/Al-MCF materials was investigated in the hydrogenation of p-nitrophenol (PNP) to p-aminophenol (PAP) using NaBH4 as a reducing agent. Significant differences in catalytic activity for the prepared catalysts were observed, with a superior catalytic activity of Pd/Al-MCF as compared to Pd/Al-SBA-15. Furthermore, investigations on external mass-transfer limitations of the reaction conducted with two selected supported Pd catalysts were conducted and discussed.