Studies of adsorbed species of CO, H-2 and CO/H-2 over ZrO2

The adsorption of CO, H-2 and CO/H-2 on ZrO2 was investigated by in situ FT IR. H-2 species adsorbed over ZrO2 produced two bands at 3 780 and 3 680 cm (-1), corresponding to ZrOHZr and ZrOH, respectively. CO adsorbed on ZrO2 f ormed formate species at 200 degreesC, which slowly decomposed to CO with t he rise of adsorption temperature. The formate over ZrO2 could be hydrogena ted into methoxide species and methane in H-2. As a result, the hydrogenati on of methoxide, which proceeded Slowly relatively, seemed to be the rate-d etermining step.