Reaction between Nitric Oxide and Ammonia on Polycrystalline Platinum. 1. Steady-State Kinetics

Article abstract of DOI:10.1021/j100229a011

The reaction between nitric oxide and ammonia has been studied over polycrystalline platinum wires in a flow reactor at pressures between 0.2 and 1.0 torr, temperatures between 200 and 1200 deg C, and feed compositions between P_NO/P_NH3=1 and 9.Partial pressures were monitored by a differentially pumped mass spectrometer.The only products observed below 850 deg C are N2, N2O, and H2O.The rate is proportional to P_NO^-1P_NH3^1/2 and to P_NOP_NH3^1/2 at low and high temperature limits, respectively.Data can be fitted quantitatively (within 15percent at all temperatures, pressures, and compositions) by a single Langmuir-Hinshelwood (LH) rate expression.Arrhenius plots at low and high temperatures and pressures were used to obtain heats of adsorption and reaction activation energies.The propores rate expression appears to fit all steady-state rate data on this reaction on Pt between 1E-8 and 1E-3 torr between 400 and 1500 K.