Trimetallic NiMoW/Al2O3 hydrotreating catalyst based on H4SiMo3W9O40 mixed heteropoly acid

Trimetallic NiMoW/Al 2 O 3 catalyst was prepared using mixed H 4 SiMo 3 W 9 O 40 heteropoly acid of Keggin structure and nickel citrate. Bimetallic NiMo/Al 2 O 3 and NiW/Al 2 O 3 catalysts based on H 4 SiMo 12 O 40 and H 4 SiW 12 O 40 , respectively, were synthesized as reference samples. The use of mixed H 4 SiMo 3 W 9 O 40 heteropoly acid as an oxide precursor allows the tungsten sulfidation degree and the degree of promotion of active phase particles to be increased. The hydrodesulfurization activity is enhanced as compared to NiW/Al 2 O 3 catalyst. The synergistic enhancement of the activity of the NiMo 3 W 9 /Al 2 O 3 catalyst relative to the bimetallic analogs is probably caused by formation of new mixed promoted active sites for direct desulfurization.