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Quasi‐Homogeneous Oxidation of Glycerol by Unsupported Gold Nanoparticles in the Liquid Phase
Author(s) -
Skrzyńska Elżbieta,
Ftouni Jamal,
Girardon JeanSébastien,
Capron Mickaël,
JalowieckiDuhamel Louise,
Paul JeanFrançois,
Dumeignil Franck
Publication year - 2012
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.201200173
Subject(s) - chemistry , glyceric acid , catalysis , formic acid , redox , glycerol , base (topology) , inorganic chemistry , colloidal gold , nanoparticle , chemical engineering , organic chemistry , mathematical analysis , mathematics , engineering
A quasi‐homogeneous solution of gold nanoparticles prepared by the Turkevich method was used as an unconventional catalyst in the oxidation of glycerol (GLY) in the liquid phase. The highest obtained conversion was 100 % after 3 h of reaction at 100 °C under an oxygen atmosphere (5 bar). The main products were glyceric, glycolic, formic, tartronic, and oxalic acid with selectivities of 28, 36, 25, 9, and 2 %, respectively. Traces of hydroxypyruvic and acetic acid were also detected (combined selectivities below 1 %). To elucidate the reaction mechanism and specify the role of gold nanoparticles in the oxidation process, a series of experiments under various reaction conditions were carried out. The effect of reaction temperature, oxygen pressure, gold concentration, and GLY/base molar ratio was investigated. All catalytic results were systematically compared to the corresponding noncatalytic base‐induced transformations (blank tests). Such an approach allowed us to separate and clarify the respective driving parameters for the transformation of GLY (presence of a base and activity of the gold catalyst). The reaction mechanism comprised a series of oxidation and CC cleavage reactions, whereas additional oxidation–reduction reactions (of the Cannizzaro type) could also occur in the presence of the base.