Combinatorial method for the development of a catalyst promoting hydrogen uptake

Abstract

A novel optical technique to measure catalytic activity for hydrogen sorption is presented. The catalytic activity of the noble metals of Pd, Ni, Cu and Ag is studied as function of pressure and temperature. The uptake rate is limited by chemisorption as deduced by modelling kinetics. An empirical relation between uptake rate and the measured activation energy is given. The catalytic activity of NbOx is studied as a function of the oxygen concentration determined from electron spectroscopy. The measured activation energy depends strongly on the oxygen concentration and reaches a minimum of 0.6 eV at the highest oxygen content (x=2.5, i.e. Nb2O5). Pure Nb does not display a significant catalytic effect.