Influence of the size, order and topology of mesopores in bifunctional Pd-containing acidic SBA-15 and M41S catalysts for n-hexadecane hydrocracking

The catalytic performance in n-hexadecane hydrocracking of a set bifunctional catalysts composed acidic mesoporous silicas, i.e., SBA-15, MCM-41, MCM-48, and amorphous silica-alumina (ASA), Pd as acid (de)hydrogenation components, respectively, was investigated. selectivity to cracked products the occurrence secondary cracking depended on pore topology, acidity, dispersion. Si/Al ratio mesopore order SBA-15 were modified by changing pH synthesis step. Al introduced M41S materials post-synthesis grafting. All including ASA exhibited low acidity compared crystalline zeolites. Increasing content led decrease mesopores. Secondary more pronounced for containing long one-dimensional cylindrical pores (SBA-15 MCM-41) comparison with three-dimensional ordered (MCM-48) or disordered (ASA) difference is attributed differences residence time intermediates distance between sites located mesopores nanoparticles primarily outside these also influences product distribution. Ideal operation approached ASA, prepared at high