Inhibition of CoMo/HMS catalyst deactivation in the HDS of 4,6-DMDBT by support modification with phosphate

► The coking behaviour is closely related to the active sites location. ► With a high amount of P2O5 the active phase is on the support surface favouring deactivation by coke. ► The presence of P2O5 favours the sulfidation degree of Co and its promoting effect. ► Support modification with phosphate leads to enhacement of isomerisation route.