Adsorption, thermochemistry, and photochemistry of methyl formate on powdered TiO2 have been studied by Fourier-transformed infrared spectroscopy. Methyl formate is adsorbed on the TiO2 surface in two forms. One is molecularly adsorbed methyl formate showing a red-shifted carbonyl stretching. The other is a structure-reorganized species showing absorption bands at 2841, 2866, and 2942 cm-1 in the CHx stretching region. An orthoester-type intermediate is proposed to explain the observed infrared absorption bands. In the thermal reactions, all the detected carbon-containing gas products are derived from CH3O(a) and HCOO(a), which are generated as surface intermediates in the process of methyl formate decomposition. In methyl formate photochemistry, both O2 and TiO2 are essential. The origins of the gas products relating to the adsorbed species are also discussed.
All Science Journal Classification (ASJC) codes
- Physical and Theoretical Chemistry