Palladium alumina catalyst

Johnson et al. (J4) investigated the hydrogenation of a-methylstyrene catalyzed by a palladium-alumina catalyst suspended in a stirred reactor. The experimental data have recently been reinterpreted in a paper by Polejes and Hougen (P4), in which the original treatment is extended to take account of variations in catalyst loading, variations in impeller type, and variations of gas-phase composition. Empirical correlations for liquid-side resistance to gas-liquid and liquid-solid mass transfer are presented. 

Cyclopentane was cracked over a palladium-alumina catalyst at 200 C in a differential reactor (J Catal 54 397, 1978). Data of time against fractional... 

For the complete vapor-phase oxidation of methane over a palladium alumina catalyst, conversion-space-time data were taken at 350°C and 1 atm total pressure the fractional factorial design of Table X (Hll) specified the settings of the feed partial pressures of the reacting species. 

A. Rakai, D. Tessier, and F. Bozon-Verduraz, Palladium-alumina catalysts A diffuse reflectance study, New J. Chem. 16, 869-875 (1992). 

Trickle bed oxidation. Dilute aqueous ethanol (about 2-3%) is oxidized to acetic acid by the action of pure oxygen at 10 atm in a trickle bed reactor packed with palladium-alumina catalyst pellets and kept at 30°C. According to Sato et al., Proc. First Pacific Chem. Eng. Congress, Kyoto, p. 197,1972, the reaction proceeds as follows ... 

Product distributions from the reaction of the n-butenes with deuterium over palladium—alumina catalysts [124] ( D o = ( c4H8)o = 60 torr... 

Erivanskaya and co-workers also studied the dehydrocyclization of 2-n-butylnaphthalene over supported palladium, rhodium, and iridium catalysts (56-55). Palladium-alumina showed the lowest C6-dehydrocyclization activity, but was the most active for the C5-dehydrocyclization of 2-n-butyl-naphthalene. A later study showed, however, that this enhanced activity was due to the high chlorine content of the palladium-alumina catalyst and not to some mysterious inherent catalytic activity of palladium (56). 

Mahata, N., Raghavan, K. V, and Vishwanathan, V, Influence of alkali promotion on phenol hydrogenation activity of palladium alumina catalysts. Appl Catalysis A-General 1999, 182 (1), 183-187. 

Johnson et al. (J3) suggest the use of the hydrogenation reaction of a-methylstyrene with a suspended palladium-alumina catalyst as an alternative test system to establish the effect of agitation variables on liquid-phase mass-transfer coefficients. They found the over-all hydrogen transfer coefficient to vary in a complex manner with agitator speed, and to increase with the 0.6 power of the superficial gas velocity up to a point beyond which the transfer showed no further change with gas velocity. 

P10-24c The reaction of cyclopentane to form n-pentane and coke was carried out over a palladium-alumina catalyst at 290°C [/. Catal., 54, 397 (1978)]. The following conversion-time data were obtained in a constant-volume batch reactor for a catalyst concentration of 0.01 kg/m and an initial reactant concentration of 0.03 kmol/m ... 

Product JHstrUniiion from the Readion of Propylene wUh Doaterium owr Palladium-Alumina Catalysts (31)... 

Products of incomplete combustion have been shown to increase as the catalyst deactivates. Agarwal et al. report that the oxidation of a mixed stream of trichloroethylene and C5-C9 hydrocarbons over a chromia alumina catalyst produced CO equal to 32% of the total CO + CO2 with fresh catalyst. With a deactivated catalyst, CO had risen to 54% of the total carbon oxides produced. Pope et al. report products of incomplete combustion for the oxidation of 1,1,1-trichloroethane over a cobalt oxide catalyst. The cause of the catalyst deactivation has not been established, but both Agarwal et al. and Michalowiczl reference evidence of carbonaceous deposits on the catalyst after oxidation of halogenated hydrocarbons. ESCA studies by Hucknall et al. O have always shown a carbon residue on palladium alumina catalysts in addition to adsorbed halogen. 

Paze, C., Bordiga, S., Lamberti, C., Salvalaggio, M., Zecchina, A., Bellussi, G. (1997). Acidic Properties of H-p Zeolite as Probed by Bases with Proton Affinity in the 118-204 kcal moH Range A FTIR Investigation. Journal of Physical Chemistry B, Vol.101, No.24, (June 1997), pp. 4740-4751, ISSN 1520-6106 Peri, J.B. (1965). A Model for the Surface of y-Alumina. Journal of Physical Chemistry, VoL69, No.l, (January 1965), pp. 220-230, ISSN 0022-3654 Pillo, T., Zimmermann, R., Steiner, P., Hufner, S. (1997). The Electronic Structure of PdO Found by Photoemission (UPS and XPS) and Inverse Photoemission (BIS). Journal of Physics Condensed Matter, Vol.9, No.l9, (May 1997), pp. 3987-3999, ISSN 0953-8984 Rakai, A., Tessier, D., Bozon-Verduraz, F. (1992). Palladium-Alumina Catalysts - a Diffuse Reflectance Study. New Journal of Chemistry, Vol.16, No.8-9, (August-September 1992), pp. 869-875, ISSN 1144-0546... 

Greca, M.C., Moraes, C., Segadaes, A.M. Palladium/alumina catalysts effect of the processing route on catalytic performance. Appl. Catal. A 26, 267-276 (2001)... 

Hoost TE, Otto K. Temperature-programmed study of the oxidation of palladium alumina catalysts and their lanthanium modification. Appl Catal A Gen. 1992 92(l) 39-58. 

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