Methanol synthesis reactions over a CuZr based catalyst investigated usingperiodic variations of reactant concentrations

The application of the modulation concept to study the reaction pathway and the reaction rate constants of the methanol synthesis starting from CO and CO2 over a CuZr based catalyst is described. Kinetic data of different rea ction steps can be calculated by performing modulation experiments using di fferent feed gas compositions. The dynamic variations in the concentrations of products, intermediates and reactants are monitored in situ in a DRIFT cell. The observed retardation (phase shift Delta phi) is examined dependin g on the modulation frequency omega. This method is used to derive equilibr ium and overall rate constants characterising the investigated reaction ste ps. By repeating the experiments at different reaction temperatures, consta nts such as Arrhenius activation energies can be assessed. (C) 2001 Elsevie r Science B.V. All rights reserved.