Hydrogenation of propene

Compared with the extensive studies of the kinetics of ethylene hydrogenation, the kinetics of the hydrogenation of propene have received little attention. Over platinum—pumice catalysts at 18° C, the kinetic rate law was observed to be 

The reaction of propene with deuterium has been studied over a variety of catalysts [92,103,105,118]. Some typical deuteropropane and deutero-propene distributions are shown in Table 8. Values of j3e as defined in Sect. 3.3 and a (Sect. 3.4) are also quoted. 

Comparison of these results with those presented for ethylene in Table 7 show that, for each catalyst, the two reactions show close similarities suggesting that the general features of the mechanisms are the same for both reactions. There are some important differences in detail between the two reactions, particularly with palladium and iridium. With palladium, olefin exchange occurs more readily with propene than with ethylene. This may be due to easier desorption of propene or possibly due to an alternative mechanism such as 

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Ionic liquids have already been demonstrated to be effective membrane materials for gas separation when supported within a porous polymer support. However, supported ionic liquid membranes offer another versatile approach by which to perform two-phase catalysis. This technology combines some of the advantages of the ionic liquid as a catalyst solvent with the ruggedness of the ionic liquid-polymer gels. Transition metal complexes based on palladium or rhodium have been incorporated into gas-permeable polymer gels composed of [BMIM][PFg] and poly(vinyli-dene fluoride)-hexafluoropropylene copolymer and have been used to investigate the hydrogenation of propene [21]. 

Write equations to show the hydrogenation of propene with the catalyst H3Co(P[Pg.813]

The theoretical study of the structure of propene was then used as a model to calculate the effect of the structure on the proton affinity, and later to predict the acidity of similar systems such as cycloalkenes46. Deformation of the CCC angle as a function of the stability of the anion was probed, and the results were in agreement with the acidities of the hydrogens of propene. The allylic protons were found to be more acidic than the vinylic ones, which is in contrast to the results of Grundler47. 

C. Aaserud, A. M. Hilmen, E. Bergene, S. Eri, D. Schanke and A. Holmen, Hydrogenation of propene on cobalt Fischer-Tropsch catalysts, Catal. Lett., 2004, 94, 171-176. 

Thermodynamics of hydroformylation and hydrogenation of propene at standard conditions are as follows ... 

Figure 1.13 Hydrogenation of propene to propane in the presence of a supported metal catalyst (the reverse arrows are omitted for clarity).

EXAFS Results Characterizing Supported Metal Clusters During Catalytic Hydrogenation of Propene Fed in an Equimolar Mixture to a Flow Reactor Operated at Steady State at 25°C and 1 atm (Panjabi, Argo, and Gates, 1999)a... 

Table 1.4.1 Kinetic parameters for the simultaneous hydroformylation and hydrogenation of propene over a rhodium zeolite catalyst at 7" = 423 K and 1 atm total pressure [from Rode et al., J. Catal., 96 (1985) 563].

Similar conclusions have been drawn from a study of the hydrogenolysis and isomerization of cyclopropane over catalysts made up of supported rhenium clusters of differing nuclearity.29 The hydrogenolysis of cyclopropane was found to take place only over those catalysts having at least a Re3 nuclearity while the hydrogenation of propene, an isomerization product of cyclopropane, took place on Re I species (Eqn. 3.1). 

Both Pd- and Pt-based systems are very active in propene and hydrogen conversion, but both catalyze the hydrogenation of propene. Nevertheless, an outstanding PO yield of 11.7% (selectivity 46%) vas obtained on a TS-1 catalyst loaded with 1 wt%... 

Scott K, Basov N, Jachuck RJJ, Winterton N, Cooper A, Davies C (2005) Reactor studies of supported ionic liquids rhodium-catalysed hydrogenation of propene. Chem Eng Res Des 83 1179-1185... 

Figures 6 and 7 show the hydrogenation of propene over MoH-mordenite (6.1 wt % Mo, 1.95 Mo/unit cell). The fully reduced form (Mo5+) exhibits significant hydrogenation ability, however the oxidised form (Mo6+) exhibits almost pure metathesis. It is generally accepted that the lower the oxidation state of Mo the greater the rate of hydrogenation (refs. 9,10). The rate must be significantly low over the fully oxidised form that the metathesis reaction predominates (some propane is observed), and hydrogen has the affect of inhibiting acid-catalysed secondary reactions.

Catalysts prepared by method HDP-I, with a Au loading of 1 wt% or 3 wt%, showed a very high activity for hydrogenation of propene to propane at 323 K, in agreement with data provided by Haruta.41 Also minor amounts of acetone were produced. Catalytic activity for the formation of PO from... 

Fig. 10. Turnover frequency TOF versus fraction exposed FE and mean particle size d for the hydrogenation of propene, 1-hexene, and cyclopropanes on various metal systems (see Table V for details of the studies).

Fig. 4. Hydrogenation of propene in the presence of LaNi4Fe time- and temperature-related evolution of the amount of propene hydrogenated (Barrault et al. 1986c).

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