A STUDY OF CHEMISORPTION BEHAVIOR OF CARBON-MONOXIDE ON RHODIUM SURFACES

By using a high resolution voltage-pulsed atom-probe (HRVP AP), we have studied the chemisorption behavior of CO on Rh(111), (001) and (113) planes and their vicinal stepped surfaces at low coverage. The results convincingly show that CO is adsorbed only molecularly on the Rh(111) and (001) planes and with a trace of dissociation on the higher index (113) plane. However, CO dissociates significantly on the stepped vicinities of these planes when the density of steps is high. Evidence has been found proving that closely spaced step and kink sites play a major role in promoting dissociation of adsorbed CO under our experimental conditions. The results are consistent with our previous report. © 1990.