Characterization of XMoO3 · YNiO/USHY zeolites by i.r., XPS, EXAFS, and catalytic HDS of thiophene: The influence of metal loading and preparation procedure

A series of MoO3, NiO, and MoO3 + NiO on ultrastable HY zeolite (USHY) catalysts with different oxide loading and different procedures of preparation have been studied by i.r., XPS, and EXAFS. It has been found that molybdenum and nickel species are highly dispersed, and both oxides can be found in the supercages of the Y zeolite. In the case of NiO + MoO3/USHY catalysts, an interaction between nickel and molybdenum is established through oxygen bonds. The degree of interaction depends on the order of incorporation of the metals and on the Ni/Mo ratio. The HDS activity of the samples for thiophene is related to the degree of Ni-O-Mo interaction.