Desorption activation energy distribution function of nitric oxide chemisorbed on carbonaceous materials at 373 K Original Research Article

The distribution function for the activation energy of NO desorption from carbonaceous materials treated with mixtures of NO, NO/O2 and NO/H2O/O2 at 373 K, was determined. The algorithm employed in the calculation was a variation of the stochastic method commonly used for the evaluation of the activation energies from TPD data. The calculated distribution function is a combination of two normal distribution functions, centered at energies around 150 and 190 kJ/mol which corresponds to the desorption of NO from organic structures as was previously determined by XPS analysis. The higher activation energy complex is promoted by the catalytic activity of the mineral matter in the char. Molecular oxygen enhances the NO reversible chemisorption while water partly inhibits this effect.