Gy. Popova et al., In situ FTIR study of the adsorption of formaldehyde, formic acid, and methyl formiate at the surface of TiO2 (anatase), KINET CATAL, 41(6), 2000, pp. 805-811
The catalytic properties of TiO2 (anatase) in the reactions of formaldehyde
oxidation and formic acid decomposition are examined. At 100-150 degreesC,
formaldehyde is converted into methyl formate with high selectivity regard
less of the presence of oxygen in the reaction mixture. Formic acid is deco
mposed to CO and water. Surface compounds formed in the reactions of formal
dehyde, formic acid, acid methyl formate with TiO2 (anatase) are identified
by in situ FTIR spectroscopy. In a flow of a formaldehyde-containing mixtu
re at 100 degreesC, H-bonded HCHO, dioxymethylene species, bidentate format
e, and coordinatively bonded HCHO are observed on the TiO2 surface. In the
adsorption of formic acid, H-bonded HCOOH and two types of formates (bident
ate and unsymmetrical formates) are formed. In the adsorption of methyl for
mate, H-bonded HCOOCH3, HCOOCH3 coordinatively bonded via the carbonyl oxyg
en, and bidentate formate are identified.