Role of Pt in Pt/SO42--ZrO2 catalyzed n-butane isomerization reaction: Hydrogen spillover rather than bifunctional "metal-acid" catalysis

The understanding of reaction mechanism is the key to develop the highly efficient catalyst. The introduction of Pt on SO42-/ZrO2 surface greatly improves its catalytic stability in n-butane hydroisomerization, but the function of Pt is still in controversy. The introduction of Pt on sulfated zirconia surface only promotes the hydrogenation of coke precursor and slows catalyst deactivation during n-butane hydroisomerization, but has no effect on the initial conversion rate of n-butane and selectivity to isobutane. H2-TPR and H2-TPD investigations reveal that Pt functions via hydrogen spillover mechanism, rather than classical bifunctional "metal-acid" catalysis mechanism. Our findings provide a new perspective for the rational design and synthesis of "metal-acid" bifunctional catalysts for alkane isomerization.