FTIR and Mass-Spectrometric Measurements of the Rate Constant for the C6H5 + H2 Reaction

Abstract

The rate constant for the C6H5 + H2 → C6H6 + H reaction has been measured by pyrolysis/Fourier transform infrared spectrometry (P/FTIRS) in the temperature range of 548−607 K and by pulsed-laser photolysis/mass spectrometry (PLP/MS) in the temperature range of 701−1017 K. By P/FTIRS, the reaction was studied by measuring time-resolved concentration profiles of the reactant (C6H5NO) and the product (C6H6) using highly diluted mixtures of C6H5NO in H2 (with or without Ar dilution). In PLP/MS experiments, the C6H5 radical was generated by the photolysis of C6H5COCH3 at 193 nm in the presence of several Torr of H2. The C6H5 + H2 rate constant was determined by the absolute yields of C6H6 and C6H5CH3 products. The results of these two spectrometric measurements agree closely with our theoretically predicted expression, k = 5.72 × 104T2.43 exp (−3159/T) cm3/(mol·s) and with that of a shock-tube study by Troe and co-workers (ref 20) in the temperature range of 1050−1450 K. Preliminary kinetic data on the CH3 + C...