Hydrogen and alkanes

Huber, G. W. Dumesic, J. A., An overview of aqueous-phase catalytic processes for production of hydrogen and alkanes in a biorefinery. Catalysis Today 2006, 111, 119. 

Figure 6.11 Hydrogen and alkane selectivity for reforming of 10wt% aqueous EG at 225 °C and 22 bar (adapted from Ref [289]).

The elementary reaction steps of the hydrocarbons considered in this section are summarized in Fig. 8. Tlie occurrence of monomolecular reactions with linear hydrocarbons that produce hydrogen and alkane fragments was first demonstrated by Haag and Dessau [94], For convenience, the zeolite lattice to which the proton is attached is not explicitly shown in the scheme. However, it will become clear later that proton activation cannot be understood properly without explicitly taking into account the interaction of the carbonium and carbenium ion intermediates with the negatively charged zeolite wall. 

Davda, R.R., Shabaker, J.W, Huber, G.W. et al. (2005) A review of catalytic issues and process conditions for renewable hydrogen and alkanes by aqueous-phase reforming of oxygenated hydrocarbons over supported metal catalysts. Applied Catalysis B, 56 (1-2), 171-186. 

Metal clusters in zeolites are catalysts for a number of reactions, including alkene hydrogenation and alkane hydrocracking. The former is an example of shape selective catalysis, whereby straight diain alkenes can enter the zeolite pores and react but branched alkenes cannot enter and so do not substantially react. The latter have been apidied commerdally. Pt dusters in the zeolites KL and BaKL are remarkably selective catalysts for the dehydroi dization of n-hexane to give benzene, and they are now applied commerdally. The origin of the selectivity is still not fully understood, but it may be primarily a consequence of the smallness of the Pt clusters, which consist of only about S or 6 atoms on average, as determined by EXAFS spectroscopy, H2 chemisorption, and electron microscopy. 

Hydrocarbons are molecules that contain only carbon and hydrogen, and alkanes are hydrocarbons that have only carbon-carbon single bonds and carbon-hydrogen bonds with the generic formula C H2 +2 ... 

Davda, R., Shabaker, W., Huber, W., Cortright, D. Dumesic, A. (2005). A Review of Catalytic Issues and Process Conditions for Renewable Hydrogen and Alkanes by Aqueous-phase Reforming of Oxygenated Hydrocarbons over Supported Metal Catalysts. Applied Catalysis B Environmental, Vol. 56, No. 1-2, (March 2005), pp. 171-186, ISSN 09263373... 

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