Kinetic explosion and bistability in adsorption and reaction of acetic acid on Pd(110)

The adsorption and reaction of acetic acid with Pd(110) have been studied using thermal molecular beam reaction measurements and temperature-programmed desorption. Acetic acid adsorption results in the formation of acetate species which decompose to produce coincident CO2 and H-2 desorption from the surface. C is deposited on the surface from the dehydrogenation of the methyl group. In combination, these steps are found to exhibit unusual kinetics including (i) a '' surface explosion '' during heating and (ii) bistability in the reaction pro. le for heating and cooling curves. This is the first report of such behaviour for a complex system during in situ reaction.