Kinetic analysis of N2O decomposition over calcined hydrotalcites

摘要

Kinetics of N2O decomposition over catalyst prepared by calcination of Co-Mn hydrotalcite was examined in integral fixed-bed reactor (V/w = 12-961g(cat)(-1) h(-1)) at various N2O and O-2 initial partial pressure at temperature range of 330-450 degrees C. Kinetic data were evaluated by linear and non-linear regression method, 15 kinetic expressions were tested. Based on the obtained results a redox model of NO decomposition was proposed. At low pressures of O-2, adsorbed oxygen is formed by the N2O decomposition; the N2O chemisorption is considered as the rate-determining step. On the contrary, at high O-2 pressure it could be assumed that adsorbed oxygen species appear as a result of O-2 adsorption and the Eley-Rideal mechanism is the rate determining. N2O decomposition is well described by the 1 st rate law at N2O and O-2 concentrations typical for waste gases. (c) 2006 Elsevier B.V. All rights reserved.