Temperature programmed reduction studies

Choisnet, J Abadzhieva, N Stefanov, P Klissurski, D Bassat, JM Rives, V Minehev, L. X-ray photoeleetron spectroscopy, temperature-programmed desorption and temperature-programmed reduction study of LaNiOs and La2Ni04+s catalysts for methanol oxidation. J. Chem. Soc., Faraday Transactions, 1994, Volume 90, 1987-1991. 

Temperature-Programmed Reduction Studies. The temperature programmed reduction (TPR) system, built in-house, is shown schematically in Figure 2. The same system was also used for temperature programmed desorption studies. The TPR profiles were determined by heating samples (50 mg) at a rate of 5 °C per minute from 50 °C to 950 °C. The temperature was then held at 950 °C until the reduction was completed. The reducing gas was 6 % H2 in N2, and the... 

M. C., Moulijn, J.A., Medema, J., de Beer, V.H.J. and Gellings, P.J. (1980) Vanadium oxide monolayer catalysts. 3. A Raman spectroscopic and temperature-programmed reduction study of monolayer and crystal-type vanadia on various supports. J. Phys. Chem., 84, 2783. 

Ge, X. and H. Zhang. 1998. Temperature programmed reduction studies of V-Ag catalysts. J. Solid State Chem. 141 186-190. 

Figure 5 Temperature programmed reduction studies of Mo03/Zr02 catalysts...

Calcination and Reduction of Co/Al Hydroxycarbonates. As found with the Co/Al clays, temperature programmed reduction studies revealed that pre-calcination in air was necessary to produce a metallic cobalt-containing catalyst at reasonable reduction temperatures ... 

S. and Jackson, S.D. (2005) On the structure of vanadium oxide supported on aluminas UV and visible Raman spectroscopy, UV-visible diffuse reflectance spectroscopy, and temperature-programmed reduction studies. Journal of Physical Chemistry, 109, 2793-800. 

For Temperature Programmed Reduction Studies (TPR) the heating rate used was 0.2°C/s. The H2 and Ar flow rates used were 0.48 ml/min and 7.1 ml/min respectively. Where calcined catalysts were used, the sample size was approximately 40 mg, whereas the TPR profiles of activated catalysts were obtained using 0.25 g samples. The activation procedure used was as described for FT screening. The temperature range was from room temperature to 800°C. 

S. Gobalos, N. Mahata, I. Sajo, M. Hegediis, I. Borbath and J. L. Margitfalvi, "Hy-drogenolysis of Ethyl Laurate on Ru-Sn/y-ALOs Catalysts Prepared by Impregnation II. X-ray Diffraction and Temperature Programmed Reduction Study" submitted to Catal. Lett. 

Blaser, H.U., Jalett, H.P., Monti, D.M., Wehrli, J.T. (1989) Enantioselective hydrogenation of alpha-keto esters temperature-programmed reduction study of liquid-phase Pt-Alumina hydrogenation catalysts, Appl. 

Roozeboom, F., Mittehneijer-Hazeleger, M., Mouhjn, J., et al. (1980). Vanadium Oxide Mono-layer Catalysts. 3. A Raman Spectroscopic and Temperature-programmed Reduction Study of Monolayer and Crystal-type Vanadia on Various Supports, J. Phys. Chem., 84, pp. 2783-2791. Saleh, R., Wachs, L, Chan, S., et al. (1986). Comparison of Vanadium Pentoxide/Titanium Oxide (anatase) and V205/Ti02 (Rutile) Promoting Effect of the Support, Preprints ACS Div. of Petroleum Chemistry, 31, pp. 272-276. 

Li C, Chen YW. Temperature-programmed-reduction studies of nickel oxide/alumina catalysts effects of the preparation method. Thermochim Acta. 1995 256 457. 

Catalytic Reduction of SO3 Stored in SOx Transfer Catalysts -A Temperature-Programmed Reaction Study... 

In this study butyl acetate (AcOBu) was hydrogenolysed to butanol over alumina supported Pt, Re, RePt and Re modified SnPt naphtha reforming catalysts both in a conventional autoclave and a high throughput (HT) slurry phase reactor system (AMTEC SPR 16). The oxide precursors of catalysts were characterized by Temperature-Programmed Reduction (TPR). The aim of this work was to study the role and efficiency of Sn and Re in the activation of the carbonyl group of esters. 

The pros and cons of oxidative dehydrogenation for alkene synthesis using doped cerianites as solid oxygen carriers are studied. The hydrogen oxidation properties of a set of ten doped cerianite catalysts (Ce0.9X0.1Oy, where X = Bi, In, La, Mo, Pb, Sn, V, W, Y, and Zr) are examined under cyclic redox conditions. X-ray diffraction, X-ray photoelectron spectroscopy, adsorption measurements, and temperature programmed reduction are used to try and clarify structure-activity relationships and the different dopant effects. 

Structural characterization of the prepared Co/alumina catalysts was studied by using the following techniques Brunauer-Emmett-Teller (BET), temperature-programmed reduction (TPR), H2 chemisorption by temperature-programmed desorption (TPD) with 02 pulse reoxidation, and powder x-ray diffraction (XRD). 

Catalysts used in the temperature programmed reduction (TPR) study were granular and are described in Table II. These catalysts were made by... 

Figure 6.20 shows an example in which QEXAFS has been used in combination with XRD to study the temperature programmed reduction of copper oxide in a Cu/ZnO/Al203 catalyst for the synthesis of methanol [43,44]. Reduction to copper metal takes place in a narrow temperature window of 430-440 K, and is clearly revealed by both the EXAFS pattern and the appearance of the (111) reflection of metallic copper in the XRD spectra. Note that the QEXAFS detects the metallic copper at a slightly lower temperature than the XRD does, indicating that the first copper metal particles that form are too small to be detected by XRD, which requires a certain extent of long range order [43,44],... 

Temperature Programmed Reduction (TPR) Studies. In the TPR studies, a gas mixture of 2% H2 in Ar is passed over powdered samples of the calcined catalysts. The catalysts are held in the middle of a 5-mm diameter, 0.4-m long quartz reactor with... 

Penkova, A., Dzwigaj, S., Kefirov, R., Hadjiivanov, K., and Che, M. (2007) Effed of preparation method on the state of BEA zeolites. A study by Fourier transform Ir spectroscopy of adsorbed CO and NO, temperature programmed reductions, and x-ray... 

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