CHEMISORPTION AND OXIDATIVE INTERACTION OF TRIMETHYLAMINE ON RU/TIO2

The adsorption of trimethylamine (TMA) at room temperature (RT) and its oxidative interaction on TiO2 and Ru/TiO2 until 773 K has been studied by FTIR. TMA is molecularly chemisorbed on the coordinatively unsaturated (cus) Ti4+ Lewis centers of the support at RT and is only slowly oxidized at this temperature. A first oxidation, leading to dimethylformamide (DMF) water and formate species, occurs at 473 K on both the samples. At 573 K DMF is destroyed in O2 giving different products on TiO2 and Ru/TiO2; on the latter a more complete oxidation occurs, giving nitrosyl species adsorbed on the Ru phase and nitrate species, water and formates on the titania. The formation of these species can be correlated with the high efficiency of this system as TMA sensor.