Adsorption and reduction of nitrogen monoxide by potassium-doped carbon
Abstract
Neither the adsorption nor the reduction of nitrogen monoxide occurs at 360 °C on pure carbon, but significant reduction of NO, giving N2 and CO2, proceeds on potassium-doped carbons. The uptake of NO on carbon is increased markedly by doping potassium salts and the adsorbed NO undergoes decomposition and/or desorption giving N2O (25–250 °C), NO (250–400 °C) and CO2(400 °C) in vacuum. Isotope labelling experiments using 15NO and N218O suggest that the N2O is produced by the decomposition of (NO)2(a) and that the NO and CO2 are caused by the reaction of NO2(a) with carbon. O(a) and NO2(a) are the predominant species during the reaction of NO on K-doped carbon, and NO2(a) suppresses the reaction of NO with carbon.