Butane isomerization catalysis

Z. Hong, K.B. Fogash, and J.A. Dumesic, Reaction kinetic behavior ofsulfated-zirconia catalysts for butane isomerization, Catalysis Today 51, 269-288 (1999). 

An IR study of SbF5-Al203 after addition of pyridine to the catalyst shows an absorption at 1460 cm-1, which is assigned to pyridine coordinated with the Lewis acid site, and shows another absorption at 1540 cm-1, which is attributed to the pyridinium ion resulting from the protonation of pyridine by the Brpnsted acid sites. When the catalyst is heated up to 300°C, the IR band of the pyridinium ion disappears, whereas the absorption for the Lewis acid is still present. The fact that the catalyst is still active for ra-butane isomerization suggests that the Lewis acid sites are the active sites for the catalysis.111... 

Metal halide supported on sulfonic acid resin AlClj - sulfonic acid resin Catalysis of n-butane isomerization 2 X 10 ... 

Ileteropoly compound CsrdfosPWijO o llo = -15 catalysis of n-butane isomerization ... 

Promoted sultated zirconia I e-, Mn-proinoted S(V -ZKh Catalysis of n-butane isomerization 7 X lO" ... 

Figure 2 Adsorption possibilities for 2,2-dimethyl butane leading to various hydrogenolysis and isomerization possibilities. (Based on Advances in Catalysis. 1983, 3, 149)...

Before the war, using one of the earliest samples of tritium from the Radiation Laboratory c.t Berkeley, he found the rate of isomerization of n-butane to isobutane, over aluminum chloride promoted with water, was proportional to the rate of exchange of hydrogens between the hydrocarbon and a catalyst promoted with tritiated water. This observation may have been part of the stimulus for the more detailed studies with isotopic tracers of acid catalysis after the war. 

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