Monomeric Copper(II) Sites Supported on Alumina Selectively Convert Methane to Methanol

Monomeric Cu^II sites supported on alumina, prepared using surface organometallic chemistry, convert CH₄ to CH₃ OH selectively. This reaction takes place by formation of CH₃ O surface species with the concomitant reduction of two monomeric Cu^II sites to Cu^I , according to mass balance analysis, infrared, solid-state nuclear magnetic resonance, X-ray absorption, and electron paramagnetic resonance spectroscopy studies. This material contains a significant fraction of Cu active sites (22 %) and displays a selectivity for CH₃ OH exceeding 83 %, based on the number of electrons involved in the transformation. These alumina-supported Cu^II sites reveal that C-H bond activation, along with the formation of CH₃ O- surface species, can occur on pairs of proximal monomeric Cu^II sites in a short reaction time.