An FT-IR study of the adsorption of urea and ammonia over V2O5-MoO3-TiO2SCR catalysts

A model V2O5-MoO3-TiO2 DeNO(x) catalyst has been prepared and briefly chara cterized. The adsorption of urea on it (and of ammonia for comparison) has also been investigated. It has been observed that urea can adsorb over the catalyst in an anionic form that can later decompose to isocyanate anions a nd ammonia and ammonium ion species. This mechanism suggests that the poten tial reactivity of the anionic form of urea and of isocyanate anions with V OCs, if they are present in the waste gas, possibly rise to polluting compo unds must be taken into account for applications of the urea/DeNO(x) proces s. (C) 2000 Elsevier Science B.V. All rights reserved.