Surface interaction of Ni/Mo oxides on ultrastable Y zeolites

The interactions of NiO, MoO3 and their mixtures with the acid surface of an H-Y ultrastable zeolite have been studied on a series of samples. These samples were prepared by impregnation, calcination and reduction, (if necessary), of Ni and Mo salts, on an H-Y ultrastable zeolite (HYUS). By using i.r. spectroscopy and X-ray diffraction techniques it has been observed that MoO3 interacts with most of the hydroxyl groups while NiO interacts only with those appearing at 3640 and 3550 cm−1. In the samples containing both oxides a strong interaction between them is shown, while the acidity of the original HYUS is partially regenerated. The influence of the order of impregnation on the final acidity of the zeolite is also discussed.