Research output: Contribution to journal › Article › peer-review
Highly Efficient Catalysts Based on Divanadium-Substituted Polyoxometalate and N-Doped Carbon Nanotubes for Selective Oxidation of Alkylphenols. / Evtushok, Vasiliy Yu; Suboch, Arina N.; Podyacheva, Olga Yu et al.
In: ACS Catalysis, Vol. 8, No. 2, 02.02.2018, p. 1297-1307.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Highly Efficient Catalysts Based on Divanadium-Substituted Polyoxometalate and N-Doped Carbon Nanotubes for Selective Oxidation of Alkylphenols
AU - Evtushok, Vasiliy Yu
AU - Suboch, Arina N.
AU - Podyacheva, Olga Yu
AU - Stonkus, Olga A.
AU - Zaikovskii, Vladimir I.
AU - Chesalov, Yurii A.
AU - Kibis, Lidiya S.
AU - Kholdeeva, Oxana A.
N1 - Publisher Copyright: © 2018 American Chemical Society.
PY - 2018/2/2
Y1 - 2018/2/2
N2 - Alkyl-substituted benzoquinones serve as versatile building blocks for a variety of biologically active compounds. In this work, we present an approach for the environmentally benign synthesis of alkyl-p-benzoquinones, in particular trimethyl-p-benzoquinone (TMBQ, vitamin E precursor), which employs aqueous hydrogen peroxide as oxidant and a divanadium-substituted γ-Keggin polyoxotungstate, [γ-PW10O38V2(μ-O)(μ-OH)]4- (V2-POM), immobilized on nitrogen-doped carbon nanotubes (N-CNTs) as heterogeneous catalyst. A series of supported catalysts V2-POM/N-CNTs containing 5-25 wt % of V2-POM and 0-4.8 atom % of N has been prepared and characterized by elemental analysis, N2 adsorption, SEM, TEM, XPS, and FTIR techniques. The catalytic performance of V2-POM/N-CNTs was assessed in the selective oxidation of 2,3,6-trimethylphenol (TMP) with H2O2 under mild reaction conditions (60 °C, MeCN). The presence of nitrogen in the support ensures strong adsorption and molecular dispersion of V2-POM on the carbon surface, leading to highly active and selective heterogeneous catalysts, which do not suffer from metal leaching and can be used repeatedly without loss of the catalytic performance. By application of the optimal catalyst V2-POM/N-CNTs enclosing 15 wt % of V2-POM and 1.8 atom % of N, TMBQ could be obtained with 99% yield and 80% oxidant utilization efficiency. The catalyst demonstrated the truly heterogeneous nature of the catalysis and high turnover frequencies (500 h-1) and space-time yield (450 g L-1 h-1). FTIR and XPS techniques confirmed the stability of V2-POM and N-CNT support under the turnover conditions.
AB - Alkyl-substituted benzoquinones serve as versatile building blocks for a variety of biologically active compounds. In this work, we present an approach for the environmentally benign synthesis of alkyl-p-benzoquinones, in particular trimethyl-p-benzoquinone (TMBQ, vitamin E precursor), which employs aqueous hydrogen peroxide as oxidant and a divanadium-substituted γ-Keggin polyoxotungstate, [γ-PW10O38V2(μ-O)(μ-OH)]4- (V2-POM), immobilized on nitrogen-doped carbon nanotubes (N-CNTs) as heterogeneous catalyst. A series of supported catalysts V2-POM/N-CNTs containing 5-25 wt % of V2-POM and 0-4.8 atom % of N has been prepared and characterized by elemental analysis, N2 adsorption, SEM, TEM, XPS, and FTIR techniques. The catalytic performance of V2-POM/N-CNTs was assessed in the selective oxidation of 2,3,6-trimethylphenol (TMP) with H2O2 under mild reaction conditions (60 °C, MeCN). The presence of nitrogen in the support ensures strong adsorption and molecular dispersion of V2-POM on the carbon surface, leading to highly active and selective heterogeneous catalysts, which do not suffer from metal leaching and can be used repeatedly without loss of the catalytic performance. By application of the optimal catalyst V2-POM/N-CNTs enclosing 15 wt % of V2-POM and 1.8 atom % of N, TMBQ could be obtained with 99% yield and 80% oxidant utilization efficiency. The catalyst demonstrated the truly heterogeneous nature of the catalysis and high turnover frequencies (500 h-1) and space-time yield (450 g L-1 h-1). FTIR and XPS techniques confirmed the stability of V2-POM and N-CNT support under the turnover conditions.
KW - alkylphenols
KW - benzoquinones
KW - carbon nanotubes
KW - heterogeneous catalysis
KW - hydrogen peroxide
KW - nitrogen-doped
KW - polyoxometalate
KW - selective oxidation
KW - MESOPOROUS MOLECULAR-SIEVES
KW - ELECTRICAL-CONDUCTIVITY
KW - ALLYLIC OXIDATION
KW - IONIC LIQUID
KW - ALPHA-PINENE
KW - NITROGEN
KW - AEROBIC OXIDATION
KW - HYDROGEN-PEROXIDE
KW - SILICA
KW - HETEROGENEOUS CATALYSTS
UR - http://www.scopus.com/inward/record.url?scp=85041417110&partnerID=8YFLogxK
U2 - 10.1021/acscatal.7b03933
DO - 10.1021/acscatal.7b03933
M3 - Article
AN - SCOPUS:85041417110
VL - 8
SP - 1297
EP - 1307
JO - Topics in Catalysis
JF - Topics in Catalysis
SN - 1022-5528
IS - 2
ER -
ID: 9539855