Tamara V. Andrushkevich

In situ FTIR Study of the Adsorption of Formaldehyde, Formic Acid, and Methyl Formiate at the Surface of TiO2 (Anatase)

The catalytic properties of TiO2 (anatase) in the reactions of formaldehyde oxidation and formic acid decomposition are examined. At 100–150°C, formaldehyde is converted into methyl formate with high selectivity regardless of the presence of oxygen in the reaction mixture. Formic acid is decomposed to CO and water. Surface compounds formed in the reactions of formaldehyde, formic acid, and methyl formate with TiO2 (anatase) are identified by in situ FTIR spectroscopy. In a flow of a formaldehyde-containing mixture at 100°C, H-bonded HCHO, dioxymethylene species, bidentate formate, and coordinatively bonded HCHO are observed on the TiO2 surface. In the adsorption of formic acid, H-bonded HCOOH and two types of formates (bidentate and unsymmetrical formates) are formed. In the adsorption of methyl formate, H-bonded HCOOCH3, HCOOCH3 coordinatively bonded via the carbonyl oxygen, and bidentate formate are identified.

Gas Phase Catalytic Oxidation of β-Picoline to Nicotinic Acid: Catalysts, Mechanism and Reaction Kinetics

An overview of the fundamental studies on a new method of nicotinic acid synthesis by the gas phase catalytic oxidation of β-picoline by oxygen is presented. The nature of active component in vanadia catalysts and reactivity of vanadium species are considered. Common features and differences in the mechanistic steps of nicotinic acid formation on various catalysts investigated by in situ FTIR spectroscopy are discussed. Effects of the reaction mixture components on the yield of nicotinic acid are considered in detail. Attention is paid to the kinetic equations of β-picoline oxidation on vanadia-titania catalysts.

Heterogeneous selective oxidation of formaldehyde on oxide catalysts : In situ FTIR study of formaldehyde surface species on a V-Ti-O catalyst and oxygen effect

The interaction of formaldehyde with a highly selective V-Ti-O catalyst for the oxidation of formaldehyde to formic acid is studied by Fourier-transform infrared (FTIR) spectroscopy at 70–200‡C. In a flow of formaldehyde/oxygen mixture and in a mixture without oxygen at optimal temperatures for formic acid formation (100–140‡C), methoxy groups and other oxygenates are formed in small amounts. These are two bidentate formates and covalently bound monodentate formate. The fact that similar oxygenates are observed independently of the presence of oxygen in the reaction mixture suggests the participation of the catalyst oxygen in their formation. Oxygen accelerates the desorption of bidentate formates. Bidentate formates of one type decompose in a flow of air at 100–150‡C, and bidentate formates of the other type decompose at 170–200‡C.

Role of MoVTeNb oxide catalyst constituent phases in propane oxidation to acrylic acid.

Abstract The catalytic activity of MoVTeNbO catalyst and its constituent phases (M1, M2 and Mo5O14-like) in the oxidation of propane, as well as propylene and acrolein, which are intermediates of acrylic acid formation from propane, was studied. In all the reactions, the М1 phase shows higher activity and selectivity, compared to M2 and Mo5O14-like phases; its presence being sufficient for efficient proceeding the propane oxidation to acrylic acid.