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Cu/C‐catalyzed Hydrogenolysis of Sorbitol to Glycols–On the Influence of Particle Size and Base
Author(s) -
Wang Xinde,
Beine Anna Katharina,
Hausoul Peter J. C.,
Palkovits Regina
Publication year - 2019
Publication title -
chemcatchem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.497
H-Index - 106
eISSN - 1867-3899
pISSN - 1867-3880
DOI - 10.1002/cctc.201900299
Subject(s) - hydrogenolysis , selectivity , ethylene glycol , catalysis , chemistry , particle size , propanediol , sorbitol , glycerol , ethylene , chemisorption , nuclear chemistry , organic chemistry
Herein, a series of Cu catalysts supported on activated carbon with increasing particle size was tested for the conversion of sorbitol to glycols including 1,2‐propanediol and ethylene glycol in the presence of Ca(OH) 2 . Activity measurements reveal a distinct correlation between TOF and particle size, which increases until 14 nm (N 2 O chemisorption based) after which a plateau is reached. However, variation of the particle size has no apparent effect on the selectivity for C 3 /C 3 and C 2 /C 4 cleavage. In contrast, variation of the Ca(OH) 2 equivalence has a profound impact on selectivity. The ratio of C 3 /(C 2 +C 4 ) products reaches an optimum at 0.45 equiv. of Ca(OH) 2 . Notably, the time course of the reaction demonstrates that the by‐products lactic acid and glycerol are in‐situ converted to the desired product 1,2‐propanediol, contributing to the unprecedented combined glycol selectivity of 84.5 % at 513 K, 5 MPa H 2 and 0.3 equiv. of Ca(OH) 2 . Furthermore, recycling tests reveal a rapid deactivation which is attributed to aggregation of Cu observed in TEM.