Characterisation of Basic Sites on GaO, MgO, and ZnO with Preadsorbed Ethanol and Ammonia-IR Study.

The effect of adsorption of ethanol and ammonia on the basicity of GaO, MgO, and ZnO was examined via IR studies of CO adsorption. Ethanol reacts with OH groups on GaO, and MgO, forming ethoxyl groups. The substitution of surface hydroxyls by ethoxyls increases the basicity of the neighbouring oxygen.

Determination of concentration of basic sites on oxides by IR spectroscopy.

As it is commonly known, CO reacts simultaneously with basic O and basic OH sites on oxides forming carbonates and bicarbonates, which can be followed by infrared spectroscopy (IR). However, here, we succeeded to elaborate experimental conditions under which CO reacted solely with O forming CO for ZrO and CeO, and calculated the extinction coefficients of diagnostic bands of carbonate and bicarbonate species. For the first time, the developed IR method enabled the concentrations of O and basic OH for ZrO, CeO, AlO and CuO to be measured separately.

Basic Sites on Alumina with Preadsorbed Ethanol and Ammonia-An IR Study.

The adsorption of ethanol and ammonia changes the basic properties of alumina, and new basic sites are created. Ethanol reacts with surface Al-OH groups, forming ethoxy group Al-O-CH. The substitution of Al-OH by Al-O-CH increases the negative charge of neighbouring oxygen atoms, and they became sufficiently basic to react with adsorbed CO forming carbonate species CO.

Ethoxy Groups on ZrO, CuO, CuO/ZrO AlO, GaO, SiO and NiO: Formation and Reactivity.

The reaction of ethanol with surface OH groups on ZrO, CuO/ZrO, CuO, AlO, GaO, NiO, and SiO was studied by IR spectroscopy. The basicity of oxides was followed by CO adsorption, and their ability to oxidize was investigated by H-TPR. It has been found that ethanol reacts with surface OH groups forming ethoxy groups and water.

IR Studies of Ethoxy Groups on CeO.

The reaction of ethanol with a surface of CeO was studied using IR spectroscopy. In some experiments, CeO was pretreated in a vacuum at 820 K which caused a partial reduction. In other experiments, CeO was reduced with hydrogen at 770 K.