TPD and static SIMS investigation of CO adsorption on Pd(111) during catalytic oxidation

Abstract The CO and O co-adsorption on Pd(111) under the conditions of CO catalytic oxidation (i.e. at various surface temperatures) during exposure to different CO/O 2 mixtures has been studied using the technique of thermo-programmed desorption (TPD) and static secondary ion mass spectroscopy (SSIMS). The variation of CO coverage with temperature during catalytic reaction was determined from TPD experiments. The linear relationship between the sum of ion intensity ratios Σ n Pd n CO + / Pd n + and CO coverage was found by combining the TPD and SSIMS data. The present work has confirmed that SSIMS can be used for direct investigation of the CO coverage during CO catalytic oxidation.