A new technique for studying surface reactions: the reaction of hydrogen with high pressure oxygen on palladium

We present a new technique for studying the interaction of hydrogen with high pressure co-reactants on surfaces. The sample consists of a thin Nb layer covered with a layer containing the reactive surface (i.e. Pd). The Nb layer is charged with hydrogen, and both the film resistance and the hydrogen concentration (volumetric uptake measurements) are recorded. After loading the sample with hydrogen the sample is exposed to a high pressure of the reactant (< 1 atmosphere of oxygen). After calibrating the Nb resistance against the hydrogen concentration the change in resistance is then used to monitor the rate at which hydrogen reacts with oxygen.