Polymeric hydrocarbon waste is an abundant and inexpensive source of carbon for a future sustainable chemical industry. Chemical modification of polymeric hydrocarbons face similar challenges to those encountered in the chemistry of light alkanes; these contain unpolarized sp 3 hybridized C-H and C-C bonds that are thermodynamically stable and kinetically inert. Reactive catalysts are necessary to activate these unreactive bonds. An example is the mixture of low coordinate zirconium hydrides supported on silica shown in Figure . The Zr-H sites activate a C-H bond in an alkane by a s-bond metathesis reaction 4 that follows the 4-centered transition state shown in Figure to generate the organozirconium product. A related, yet distinct, heterolytic or 1,2-addition C-H bond activation occurs on oxide surfaces. Figure shows the reaction of an alkane with a ZrO2 fragment, which follows a similar 4-centered transition state that resembles that for s-bond metathesis. This reaction is an important chemical step in hydrogenolysis of high density polyethylene catalyzed by amorphous ZrO2 nanoparticles. The two mechanisms shown in Figure are general, and are the dominant reactions that result in the activation of inert C-H bonds on oxide surfaces to form organometallic species. Both mechanisms rely on polarization of a C-H bond by a transition metal that facilitate a formal proton transfer to form the organometallic.