On the mechanism of n-butane disproportionation over platinum supported on tungstated zirconia: Isotopic labeling studies

The reactions of n-butane over platinum supported on tungstated zirconia in the presence of hydrogen were studied using isotopically labeled n-butanes and deuterium. All reaction pathways experience isotopic effects when the hydrogen flow is replaced by an equal flow of deuterium. The non-rate limiting formation of a bimolecular intermediate appears to account for the disproportionation products. Mass spectrometric analysis of the product stream also reveals that the intramolecular 1-2 shift of the labeled primary carbon atoms is easily detected under primary-product-only reaction regimes.