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
Gy. Popova et al., 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, KINET CATAL, 41(4), 2000, pp. 546-552
The interaction of formaldehyde with a highly selective V-Ti-O catalyst for
the oxidation of formaldehyde to formic acid is studied by Fourier-transfo
rm infrared (FTIR) spectroscopy at 70-200 degrees C. In a flow of formaldeh
yde/oxygen mixture and in a mixture without oxygen at optimal temperatures
for formic acid formation (100-140 degrees C), methoxy groups and other oxy
genates are formed in small amounts. These are two bidentate formates and c
ovalently bound monodentate formate. The fact that similar oxygenates are o
bserved independently of the presence of oxygen in the reaction mixture sug
gests the participation of the catalyst oxygen in their formation. Oxygen a
ccelerates the desorption of bidentate formates. Bidentate formates of one
type decompose in a flow of air at 100-150 degrees C, and bidentate formate
s of the other type decompose at 170-200 degrees C.