A Reusable Unsupported Rhenium Nanocrystalline Catalyst for Acceptorless Dehydrogenation of Alcohols through gamma-C-H Activation
Abstract
Rhenium nanocrystalline particles (Re NPs), of 2 nm size, were prepared from NH4ReO4 under mild conditions in neat alcohol. The unsupported Re NPs convert secondary and benzylic alcohols to ketones and aldehydes, respectively, through catalytic acceptorless dehydrogenation (AD). The oxidant-and acceptor-free neat dehydrogenation of alcohols to obtain dihydrogen gas is a green and atom-economical process for making carbonyl compounds. Secondary aliphatic alcohols give quantitative conversion and yield. Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Re K-edge X-ray absorption near-edge structure (XANES), and X-ray absorption fine structure (EXAFS) data confirmed the characterization of the Re NPs as metallic rhenium with surface oxidation to rhenium(IV) oxide (ReO2). Isotope labeling experiments revealed a novel gamma-CH activation mechanism for AD of alcohols.
Keywords
alcohols, dehydrogenation, heterogeneous catalysis, nanoparticles, rhenium, OXIDANT-FREE DEHYDROGENATION, ACID-BASE SITES, HETEROGENEOUS CATALYST, DEOXYDEHYDRATION, ALUMINA, DEOXYGENATION, NANOPARTICLES, COMPLEXES, OXIDATION, GLYCOLS
DOI
10.1002/anie.201307665
Date of this Version
1-13-2014
Recommended Citation
Yi, Jing; Miller, Jeffrey T.; Zemlyanov, Dmitry; Zhang, Ruihong; Dietrich, Paul J.; Ribeiro, Fabio H.; Suslov, Sergey; and Abu-Omar, Mahdi M., "A Reusable Unsupported Rhenium Nanocrystalline Catalyst for Acceptorless Dehydrogenation of Alcohols through gamma-C-H Activation" (2014). Birck and NCN Publications. Paper 1526.
http://dx.doi.org/10.1002/anie.201307665