TY - JOUR

T1 - H2O2-based selective oxidations by divanadium-substituted polyoxotungstate supported on nitrogen-doped carbon nanomaterials

AU - Evtushok, Vasiliy Yu

AU - Podyacheva, Olga Yu

AU - Suboch, Arina N.

AU - Maksimchuk, Nataliya V.

AU - Stonkus, Olga A.

AU - Kibis, Lidiya S.

AU - Kholdeeva, Oxana A.

N1 - Publisher Copyright: © 2019 Elsevier B.V. Copyright: Copyright 2020 Elsevier B.V., All rights reserved.

PY - 2020/9/1

Y1 - 2020/9/1

N2 - In this work, we present a new methodology for the preparation of highly active, selective, leaching-tolerant and recyclable catalysts on the basis of polyoxometalates (POM) and nitrogen-doped carbon nanomaterials. A divanadium-substituted γ-Keggin phosphotungstate [γ-PW 10 O 38 V 2 (μ-O)(μ−OH)] 4− (PV 2 ), was immobilized on two types of supports – N-doped carbon nanofibers (N-CNFs) having herring-bone packing of graphite layers and bamboo-like N-doped carbon nanotubes (N-CNTs). Two series of catalysts have been prepared and characterized by elemental analysis, N 2 adsorption, TEM, XPS and FTIR techniques. Their catalytic performance was assessed in the liquid-phase selective oxidation of two representative organic substrates, 2,3,6-trimethylphenol and cyclohexene, with aqueous H 2 O 2 as the green oxidant. The presence of nitrogen in the supports ensures strong binding and quasi-molecular dispersion of POM on the carbon surface, which is crucial for the catalytic performance and catalyst stability. The catalysts reveal truly heterogeneous nature of the catalysis and can be easily recovered and reused without loss of the catalytic performance. The morphology of the support has a significant impact on the catalytic performance: the supported PV 2 catalysts prepared using N-CNTs are more active and, in general, more selective than the catalysts prepared with N-CNFs.

AB - In this work, we present a new methodology for the preparation of highly active, selective, leaching-tolerant and recyclable catalysts on the basis of polyoxometalates (POM) and nitrogen-doped carbon nanomaterials. A divanadium-substituted γ-Keggin phosphotungstate [γ-PW 10 O 38 V 2 (μ-O)(μ−OH)] 4− (PV 2 ), was immobilized on two types of supports – N-doped carbon nanofibers (N-CNFs) having herring-bone packing of graphite layers and bamboo-like N-doped carbon nanotubes (N-CNTs). Two series of catalysts have been prepared and characterized by elemental analysis, N 2 adsorption, TEM, XPS and FTIR techniques. Their catalytic performance was assessed in the liquid-phase selective oxidation of two representative organic substrates, 2,3,6-trimethylphenol and cyclohexene, with aqueous H 2 O 2 as the green oxidant. The presence of nitrogen in the supports ensures strong binding and quasi-molecular dispersion of POM on the carbon surface, which is crucial for the catalytic performance and catalyst stability. The catalysts reveal truly heterogeneous nature of the catalysis and can be easily recovered and reused without loss of the catalytic performance. The morphology of the support has a significant impact on the catalytic performance: the supported PV 2 catalysts prepared using N-CNTs are more active and, in general, more selective than the catalysts prepared with N-CNFs.

KW - Hydrogen peroxide

KW - N-doped carbon nanofibers

KW - N-doped carbon nanotubes

KW - Polyoxometalates

KW - Selective oxidation

KW - LAYERED DOUBLE HYDROXIDES

KW - POLYOXOMETALATE CLUSTERS

KW - ALPHA-PINENE

KW - LIQUID-PHASE OXIDATION

KW - AEROBIC OXIDATION

KW - NANOTUBES

KW - METAL

KW - EFFICIENT

KW - HETEROGENEOUS CATALYSTS

KW - MOLECULAR-OXYGEN

UR - http://www.scopus.com/inward/record.url?scp=85063646824&partnerID=8YFLogxK

U2 - 10.1016/j.cattod.2019.03.060

DO - 10.1016/j.cattod.2019.03.060

M3 - Article

AN - SCOPUS:85063646824

VL - 354

SP - 196

EP - 203

JO - Catalysis Today

JF - Catalysis Today

SN - 0920-5861

ER -