Raman butane dehydrogenation

A comparison of the UV Raman spectrum measured for coke deposited during the MTH reaction with that deposited during butane dehydrogenation catalyzed by chromia on alumina (66) shows clear differences in the spectral intensity distribution (Fig. 11). In particular, the intensity of the features in the regions 1340-1440cm and 1560 1630 cm are nearly equal for the MTH reaction. 

Figure 15.6 UV Raman spectra of butane dehydrogenation over oxidized 1,2 V at different temperatures.

Figure 15.7 Comparison of Raman spectra from (a) styrene, (b) butane dehydrogenation over 1.2 V at 673 K and (c) a mixture of 1.2 V and styrene heated at 393 K.

It is rare for a structure-function relationship to be shown unambiguously in heterogeneous catalysis. However, a structure-coke relationship has been established in the dehydrogenation of butane on V0,/6-Al203 catalysts by combined reactivity, UV-Vis DRS, NMR, TFOM and UV Raman investigations. In this case, both the nature and amount of coke show a dependence on the structure of the V0,/6-Al203 catalysts. 

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