HDS of 4,6-DMDBT over NiW/Al-SBA15 catalysts

NiW HDS catalysts supported on alumina-modified SBA-15 were prepared using acidic solutions of ammonium metatungstate and nickel nitrate. Using this method of preparation the integrity of the SBA-15 support was preserved. The results showed that aluminum incorporation into the support framework leads to higher dispersion of the WS2 phase and gives rise to the formation of Brønsted acid sites, which in turn increase the contribution of the isomerization-direct desulfurization (ISOM-DDS) pathway of 4,6-DMDBT HDS. The higher activity displayed by the Al-modified catalysts in the HDS of 4,6-DMDBT seems to be related to the presence of Brønsted acid sites in the sulfided NiW/Al-SBA15(x) catalysts, to a higher dispersion of the WS2 phase and to the increased number of coordinatively unsaturated sites (CUS) present in the sulfided catalysts.