Studies of hydrous sodium titanate ion-exchange materials for use as catalyst supports

Understanding how the activity of a catalyst is related to the concentration and dispersion of active metals on the catalyst support is critical to designing materials having the optimum catalytic properties. We have developed synthetic techniques for controlling both the concentration and dispersion of nickel on hydrous sodium titanate catalyst supports. The techniques require an understanding of the solution chemistry of both the support material and dissolved metal species (hydrolysis products). In this paper, we present the results of a study of three nickel-loaded samples of hydrous sodium titanate in which the scale of the nickel dispersion ranges from the atomic level to the scale of large (50 nm) clusters. The catalysts are characterized by transmission electron microscopy (TEM), hydrogen chemisorption, and BET surface area measurements. In addition, the activity and selectivity of the Ni catalysts for the n-butane hydrogenolysis reaction is used to monitor the surface structures of Ni in the catalysts. 8 refs., 7 figs., 1 tab.