In the recent investigation of the NO + CO reaction over Rh catalysts supported on TiO 2 and TiO 2 (W 6+ ) carriers, Solymosi and B́nsági criticized the interpretation of the 2000-2010/cm band noted, indicating that it was due to isocyanate species adsorbed on the support and not on the Rh metal. Solymosi and Bánsági suggested that the data refer to the reaction of NCO residing on the support and had nothing to do with Rh-NCO species, since, according to their findings, the low concentration and short lifetime of NCO on Rh and other Pt-group metals prevent the establishment of their participation in this process. To resolve the issue, a set of FTIR experiments was conducted, in which the formation of isocyanate species was examined in situ under NO + CO reaction conditions over a 0.5% Rh/TiO 2 (W 6+ ) catalyst. The broad band noted in the previous studies at 2000-2010/cm, is to a large extent due to Rh-NCO, although a contribution of NCO associated with the support was also present. Thus, the present results support the previous finding related to the reactivity of Rh-NCO with NO, which provided an alternative route for the formation of N 2 O in the gas phase. The author agree with Solymosi and Bánsági about the NCO species formed on the metal and spill over onto the carrier.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry