Temperature programmed reduction/oxidation

Figure 4.20. Experimental set-ups for temperature programmed reduction, oxidation and desorption. Upper left The reactor is inside the oven, the temperature of which can be increased linearly with time. Gas consumption by the catalyst is monitored by the change in thermal conductivity of the gas mixture it is essential to remove traces of water, etc. because these would affect the thermal conductivity measurement. Lower-left ...

Temperature-programmed reaction methods form a class of techniques in which a chemical reaction is monitored while the temperature increases linearly in time. Several forms are in use temperature-programmed reduction, oxidation and sulfidation. 

Very often, temperature-programmed reduction, oxidation, sulfidation, or reaction is used to monitor the reactivity of solids. One example is given in Figure 4.3.7, in... 

Fig. 3 Temperature programmed reduction/oxidation (TPR/TPO) of cobalt oxide, monitored with in situ emission-FTIR spectroscopy. These tests were performed with -300 nm thick films in atmospheres containing 5 vol% of the reactive gas, using a temperature ramp of 4 C/min.

The experimental device used in Temperature Programmed Reduction/Oxidation (TPR/TPO) studies was similar to that described in ref [9]. The quadrupole mass spectrometer used to analyse the evolved gases was a VG Spectralab SX-200 instrument interfaced to a PC-type microcomputer. The experiments were run under the following conditions Flow rate of H2 (O2) ... 

Temperature- programmed reduction/ oxidation Reduction/reoxidation properties of redox phases in samples strong in detecting interactions between phases, in simple cases determination of energetics of reduction Nature of detected interactions remains to be elucidated no... 

Temperature-programmed Reduction, Oxidation and Reaction Spectroscopy (TPR, TPO and TPRS)... 

Temperature Programmed Reduction/Oxidation (TPR/TPO) Methods heating rate (P = dT/dt), we can write the following expression ... 

With temperature programmed reduction/oxidation method, it is possible to test the catalyst surface activity. For example, a gas phase reaction— typically cracking of a compound—is studied at various temperatures and the gas mixture coming out of the catalyst filled reactor is analyzed (generally using thermal conductivity detector, TCD) for determining the catalyst activity. 

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