Catalytic Cleavage of the C-H and C-C Bonds of Alkanes by Surface Organometallic Chemistry: An EXAFS and IR Characterization of a Zr-H Catalyst

Abstract

The catalytic cleavage under hydrogen of the C-H and C-C bonds of alkanes with conventional catalysts requires high temperatures. Room-temperature hydrogenolysis of simple alkanes is possible on a well-defined and well-characterized zirconium hydride supported on silica obtained by surface organometallic chemistry. The surface structure resulting from hydrogenolysis of (≡SiO)Zr(Np) 3 (Np, neopentyl) was determined from the extended x-ray absorption fine structure (EXAFS) and 1 H and 29 Si solid-state nuclear magnetic resonance and infrared (IR) spectra. A mechanism for the formation of (≡SiO) 3 Zr-H and (≡SiO) 2 SiH 2 and the resulting low-temperature hydrogenolysis of alkanes is proposed. The mechanism may have implications for the catalytic formation of methane, ethane, and lower alkanes in natural gas.