Structure and Stability of Formates and Carbonates on Monoclinic Zirconia: A Combined Study by Density Functional Theory and Infrared Spectroscopy

The structure and stability of formate and (bi)carbonate species were studied on monoclinic zirconia by theoretical and experimental methods. For the ab initio calculations, the most stable ((1) over bar 11) surface containing one dissociatively adsorbed water molecule was used. Infrared spectroscopy measurements were carried out on a commercial catalyst. The calculated vibrational frequencies were in good agreement with species observed by in situ infrared spectroscopy. The most stable structures for both formates and bicarbonates were bidentate formed by an insertion of CO or CO2 to the terminal hydroxyl group. The most stable carbonates were formed on Lewis acid-base pairs by the adsorption of CO2 to the undercoordinated surface sites.