The reaction between nitrogen oxides and carbon generates nitrogen-containing complexes on the carbon surface. The use of X-ray photoelectron spectroscopy allowed the characterization of these surface complexes. Five distinct structures have been distinguished, corresponding to nitrogen incorporated in five- and six-member ring as well as pyridine N-oxide and nitrate. Temperature has been found to be the determinant in the repartition of surface species. The reaction with NO-O2 at 600°C has produced both pyrrolic and pyridinic nitrogens, while the reaction with NO at 950°C mainly produced a pyridinic one. Quaternary nitrogen increased upon the heat treatment in He at 950°C after the char was reacted with NO-O2 at 600°C.
ASJC Scopus subject areas
- Chemical Engineering(all)
- Fuel Technology
- Energy Engineering and Power Technology