Identification of an adsorption complex between an alkane and zeolite active sites.

Direct observation of the Bronsted acid site signal in an active zeolite catalyst following adsorption of stoichiometric quantities of isobutane reveals the presence of a specific adsorption complex. Independent polarization transfer experiments in which magnetization originates with either the catalyst or the adsorbed isobutane confirm this assignment. The initial steps in alkane reactivity are poorly defined, and this experimentally verified complex is proposed as a route to C-H bond activation in solid acids.