Activation of Light Alkanes on Sulfated Zirconia

Abstract

The present contribution reviews recent experiments of our group towards the synthesizing and understanding of highly reactive sulfate-modified zirconia. It is shown that in the absence of Pt, the catalytic activity depends upon the ability to oxidize a small fraction of the alkanes to alkenes. The alkenes form sec-carbenium ions with Brønsted acid sites and isomerize via carbenium ion/alkoxy intermediates. Alkane activation/conversion propagates through hydride transfer from n-butane to the tert-butyl carbenium ion. A kinetic model accounting for the elementary steps is proposed and catalyst preparation strategies are reported.

Zr6O8 Node-Catalyzed Butene Hydrogenation and Isomerization in the Metal–Organic Framework NU-1000

“…Zirconia has been reported to be a dynamic catalyst and support, possessing a combination of oxidizing, reducing, acidic, and basic sites. − This renders zirconia a competent catalyst for acid, base, and acid–base bifunctionally catalyzed reactions. ,,, Zirconia can adsorb and dissociate H 2 both homolytically and heterolytically − and is thought to be an active species and/or activity-enhancing support in many critical reactions. These include olefin hydrogenation, ,− isomerization, ,, dimerization, alkane dehydrogenation, carbon dioxide and monoxide hydrogenations, − and many other reactions. ,,,,− …”