Title

Absence of the Metal-Support Interaction for Ni/TiO2 Composites Prepared Using Ion-Exchange Techniques

Document Type

Article

Subject Area(s)

Chemistry

Abstract

Many recent reports on the surface properties of transition-metalcatalysts dispersed on high surface area oxide supports have shown that the support can alter markedly the intrinsic activity of the metal. In particular, when group 8-10 metals are supported on reducible metal oxides, the surface chemistry and the electronic properties of the composite depend on the reduction temperature used for pretreatment. For example, the chemisorption of H2 at room temperature on metal-TiO2 composites decreases sharply as the reduction temperature used to prepare the catalyst is increased from 573 to 773 K. This change in surface chemistryhas been attributed to a strong interaction between the metal andthe TiOx(x < 2). By understanding the conditions required to induce this interaction, the acitivity and selectivity of supported metal catalysts can be tailored for specific applications. In this paper, we show that the extent of the interaction can be controlled if the composition at the interface between the nickel and Ti02 is manipulated by varying the method used to disperse the nickel.