TPO temperature programmed

In temperature-programmed oxidation (TPO), temperature-programmed reduction (TPR), and TPRx, the sample is exposed to a reactant gas while it is being heated. For example, examination of the desorption spectroscopy of previously adsorbed surface carbon species in a flow of hydrogen is useful for understanding the amounts and types of deactivating coke that may have formed during reaction. Different surface carbon... 

TPAT technologies include temperature programmed desorption (TPD), temperature programmed reduction (TPR), temperature programmed oxidation (TPO), temperature programmed sulfide (TPS), temperature programmed surface reaction (TPSR) and so on. TPD is the most extensively studied, widely applied and the most mature method. Hence, TPD will be focused in the following section. 

TPO (Temperature Programmed Oxidation) analyses have been carried out after catalytic tests in order to detect the amount of residual caibon from the amount of caibon-containing products (CO+CO2). The hearing program of TPO permits to reach 1000°C with a rate of 15°C/min under a mixture of oxygen (10vol%) in helium. 

TEM observation and elemental analysis of the catalysts were performed by means of a transmission electron microscope (JEOL, JEM-201 OF) with energy dispersion spectrometer (EDS). The surface property of catalysts was analyzed by an X-ray photoelectron spectrometer (JEOL, JPS-90SX) using an A1 Ka radiation (1486.6 eV, 120 W). Carbon Is peak at binding energy of 284.6 eV due to adventitious carbon was used as an internal reference. Temperature programmed oxidation (TPO) with 5 vol.% 02/He was also performed on the catalyst after reaction, and the consumption of O2 was detected by thermal conductivity detector. The temperature was ramped at 10 K min to 1273 K. 

Van t Blik H.F.J. and Prins R. 1986. Characterisation of supported cobalt and cobalt-rhodium catalysts. 1. Temperature-programmed reduction (TPR) and oxidation (TPO) of Co-Rh/Al203. J. Catal. 97 188-99. 

Instrumentation for temperature programmed investigations is relatively simple. Figure 2.1 shows the set-up for TPR and TPO studies of catalysts. The reactor,... 

Figure 9. Temperature programmed oxidation (TPO) data showing CO2 evolution m/e = 44) of thermally deposited carbon from a Cu-Ce02-YSZ SOFC anode material after exposure to n-butane for 30 min (solid line) and a graphite powder sample (dashed line). (Reprinted with permission from ref 172. Copyright 2003 The Electrochemical Society, Inc.)...

The catalytic coke produced by the activity of the catalyst and simultaneous reactions of cracking, isomerization, hydrogen transfer, polymerization, and condensation of complex aromatic structures of high molecular weight. This type of coke is more abundant and constitutes around 35-65% of the total deposited coke on the catalyst surface. This coke determines the shape of temperature programmed oxidation (TPO) spectra. The higher the catalyst activity the higher will be the production of such coke [1],... 

Other temperature-programmed techniques include Temperature Programmed Oxidation and Sulfidation (TPO and TPS) for investigating oxidation and sulfidation behaviour, and Temperature Programmed Desorption (TPD) (also called Thermal Desorption Spectroscopy [TDS]), which analyses gases desorbed from the surface of a solid or a catalyst on heating. 

Swann et al. [9] used isotopic labeling and temperature-programmed oxidation (TPO) (ex situ) approaches to show that the carbon which had formed during the C02 reforming of methane may have derived from both CH4 and C02. 

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