NOx reduction by reburning: theoretical study of the branching ratio of the HCCO plus NO reaction

The product distribution of the HCCO + NO reaction is examined theoreticall y over an extended temperature range, using RRKM-master equation analyses i ncorporating the effect of internal rotations on the state densities. The p otential energy surface was characterized at the B3LYP-DFT/6-311++G(d,p) an d CCSD(T)/6-31G(d,p) levels of theory, combined with high-level single poin t CCSD(T)/6-311++G(2d,p) calculations. The only reaction products of import ance were found to be HCNO+CO and HCN+CO2, where the predicted CO2 yield ca n be expressed as alpha (T) = 0.0652 + 0.220 exp(-T/917.9 K), for T = 300-2 500 K. The predicted product distribution is in agreement with the availabl e experimental values. (C) 2001 Elsevier Science B.V. All rights reserved.