TY - JOUR
T1 - The influence of complexing agents on the cobalt-based catalysts properties and activities
AU - Mitran, Gheorghiţa
AU - Nguyen, Tam Le Phuong
AU - Seo, Dong Kyun
N1 - Funding Information:
This work was supported by a grant from the Romanian Ministry of Education and Research, CNCS–UEFISCDI, project number PNIII-P4-ID-PCE-2020-0580, within PNCDI III.
Publisher Copyright:
© 2022 The Korean Society of Industrial and Engineering Chemistry
PY - 2022/10/25
Y1 - 2022/10/25
N2 - In this study, CoAl2O4 samples were synthesized using sol–gel method in the presence of citric acid (CoAlCA), malic acid (CoAlMA), oxalic acid (CoAlOA) and urea (CoAlU) as complexing agents. The presence of cubic spinel structure for both CoAl2O4 and Co3O4 phases was confirmed by XRD. FTIR analysis emphasized that the composition of Co3+ ions decreased in order: CoAlOA (50.3 %) > CoAlU (41.8 %) > CoAlMA (40.7 %) > CoAlCA (24.3 %), which denotes that the presence of oxalic acid as complexation agent favors cobalt oxidation from Co2+ to Co3+ and, consequently, the expansion of Co3O4 phase. In the presence of citric acid, as a complexing agent, tetrahedral Co2+ ions prevailed and CoAl2O4 is the dominant phase. The catalytic performances of CoAl2O4 spinel oxides have been evaluated in lactonization of 1,4-butanediol, coupled with acetophenone hydrogenation and in the Claisen-Schmidt condensation reaction of benzaldehyde with acetophenone and the results provided a good relationship between Co3+/Co2+ ratio, the reactants conversion and the products yield.
AB - In this study, CoAl2O4 samples were synthesized using sol–gel method in the presence of citric acid (CoAlCA), malic acid (CoAlMA), oxalic acid (CoAlOA) and urea (CoAlU) as complexing agents. The presence of cubic spinel structure for both CoAl2O4 and Co3O4 phases was confirmed by XRD. FTIR analysis emphasized that the composition of Co3+ ions decreased in order: CoAlOA (50.3 %) > CoAlU (41.8 %) > CoAlMA (40.7 %) > CoAlCA (24.3 %), which denotes that the presence of oxalic acid as complexation agent favors cobalt oxidation from Co2+ to Co3+ and, consequently, the expansion of Co3O4 phase. In the presence of citric acid, as a complexing agent, tetrahedral Co2+ ions prevailed and CoAl2O4 is the dominant phase. The catalytic performances of CoAl2O4 spinel oxides have been evaluated in lactonization of 1,4-butanediol, coupled with acetophenone hydrogenation and in the Claisen-Schmidt condensation reaction of benzaldehyde with acetophenone and the results provided a good relationship between Co3+/Co2+ ratio, the reactants conversion and the products yield.
KW - 1,4-butanediol
KW - Claisen-Schmidt condensation
KW - Cobalt aluminate
KW - γ-butyrolactone
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U2 - 10.1016/j.jiec.2022.07.035
DO - 10.1016/j.jiec.2022.07.035
M3 - Article
AN - SCOPUS:85135172357
SN - 1226-086X
VL - 114
SP - 446
EP - 455
JO - Journal of Industrial and Engineering Chemistry
JF - Journal of Industrial and Engineering Chemistry
ER -