Titania-heteropolyacid composites (TiO2-HPA) as catalyst for the green oxidation of trimethylphenol to 2,3,5-trimethyl-p-benzoquinone

Palacio, Magdalena; Villabrille, Paula Isabel; Palermo, Valeria; Romanelli, Gustavo Pablo

doi:10.1007/s10971-020-05239-6

Cited by 9 publications

(4 citation statements)

References 38 publications

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“…In the last decades, heteropolyacids (HPAs) J o u r n a l P r e -p r o o f have emerged as sustainable catalysts in Organic Chemistry due to these have been recognized as economically and environmentally benign acid catalysts due to their acidity and redox propertier for various reactions [18]. We have developed new materials based in them, for the use in the synthesis of heterocycles, eco-compatible oxidations with hydrogen peroxide, and recently in the valorization of biomass derivatives [19][20][21][22].…”

Section: Introductionmentioning

confidence: 99%

Kinetics for the biodiesel production from lauric acid over Keggin heteropolyacid loaded in silica framework

Gallego-Villada

Alarcón

Palermo

et al. 2020

Journal of Industrial and Engineering Chemistry

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Section: Introductionmentioning

confidence: 99%

Kinetics for the biodiesel production from lauric acid over Keggin heteropolyacid loaded in silica framework

Gallego-Villada

Alarcón

Palermo

et al. 2020

Journal of Industrial and Engineering Chemistry

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“…One of the most general methodologies of heterogeneity involves dispersing or immobilizing catalytically active POMs on suitable inert matrices . Quite a few supported catalytic systems including H 6 PMo 9 V 3 O 40 @C, H 3 PMo 12 O 40 /H 4 PMo 11 VO 40 @TiO 2 , H 4 PMo 11 VO 40 @SiO 2 , γ-TBA 4 HPW 10 V 2 O 40 @N-CNTs, and so on not only showed outstanding catalytic activities, which can compare favorably with those of homogeneous systems in the phenol-benzoquinone transformations, but also can easily achieve separation and reuse of catalysts. − Nevertheless, POMs will suffer from the nonhomogeneous dispersion and susceptibility to leaching in polar mediums. Currently there is considerable interest in exploiting crystalline catalytic materials that can readily elucidate the structure–activity relationship and disperse active components at the molecular level by integrating POMs and metal–organic complexes. − In this context, many excellent works have already been carried out in the oxidative cleavage of lignin, detoxification of chemical warfare agents, reduction of CO 2 , hydrogen evolution reaction, oxygen evolution reaction, reduction of Cr(VI), and other aspects by selecting POM-based metal–organic complexes as heterogeneous catalysts. − As for the oxidation of phenols to p -BQs, our group has found that Keggin-type POM-based metal–organic complexes as heterogeneous catalysts can easily realize high yields of BQs, particularly TMBQ [turnover frequency (TOF) up to 2400 h –1 ]. , However, since the accessibility of internal active sites will be blocked by the robust covalent bonding skeletons, the TOF and oxidant utilization efficiency still therefore leave room for improvement in principle.…”

Section: Introductionmentioning

confidence: 99%

Highly Efficient Supramolecular Catalysts Assembled by Dawson-Type POMs and Metal–Organic Complexes for the Synergistic Catalytic Synthesis of p-Benzoquinones

Chang

Chen

et al. 2022

ACS Sustainable Chem. Eng.

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Selective oxidation of alkyl-substituted phenols offers an ideal pathway to synthesize p-benzoquinones (p-BQs), but it is known to be inefficient because of the parallel competing reactions. Aiming at the design and synthesis of more powerful heterogeneous catalysts for highly efficient synthesizing functionalized p-BQs, herein, we report two crystalline catalysts with supramolecular networks based on Dawson-type polyoxometalates 2), where ptz = 5-(4-pyridyl)-1H-tetrazole and ina = isonicotinic acid. Structural analysis shows that 1 is formed by the supramolecular contact between one-dimensional POM inorganic chains and two kinds of trinuclear Cu-organic clusters, while 2 is formed by supramolecular stacking of ladder-like one-dimensional chains that are composed of ribbonlike nonanuclear Cu-organic clusters and POM anions. Both supramolecular catalysts exhibit high catalytic activity in H 2 O 2 -based oxidation of phenols/aromatics to p-BQs. Strikingly, in the synthesis of trimethyl-p-benzoquinone (TMBQ, an intermediate of vitamin E) by oxidizing 2,3,6trimethylphenol, the conversion, selectivity, and oxidant efficiency can reach >99, 97.9, and 85.0% for 1, as well as 95.4, >99, and 79.8% for 2 within 5 min, respectively. Also, the catalytic activities of 1 and 2 presented by the turnover frequency are 12 000 (the highest thus far) and 7632 h −1 , respectively. Detailed structure−activity analysis revealed that the higher performance of 1 is attributed to the more active-site accessibility due to the supramolecular interactions between POM and Cu organic units in the framework. Moreover, the observed yield of TMBQ has not decreased and the skeleton of catalysts has not changed in >10 cycles. The reaction mechanism was also systematically studied, and the parallel dual center, namely, Cu-site and POM, -driven reaction processes (radical and oxygen transfer) were illuminated.

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“…Despite this, these homogenous catalytic systems suffer from recycling of catalysts and purification of products. Hence, the construction of POM-based heterogeneous catalysts used for phenols oxidation is always an appealing topic. − In this aspect, Kholdeeva’s group pioneeringly immobilized TBA 4 H[γ-PW 10 O 38 V 2 (μ-O)(μ-OH)] on N-doped carbon nanomaterials for H 2 O 2 -based oxidation of alkylphenols to corresponding BQs in a nearly quantitative yield (TOF 500 h –1 ) . However, it may still suffer from other difficulties including POM leaching, low loading, non-uniform active sites, and ill-defined structure.…”

Section: Introductionmentioning

confidence: 99%

Highly Efficient Synthesis of p-Benzoquinones Catalyzed by Robust Two-Dimensional POM-Based Coordination Polymers

Chang

Chen

et al. 2021

ACS Appl. Mater. Interfaces

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Selective oxidation of alkyl-substituted phenols offers efficient access to p-benzoquinones (BQs) that serve as key components for synthesizing biologically active compounds, but rational manufacture of efficient recyclable catalysts for such a reaction remains a severe challenge. Herein, two crystalline 2D polyoxometalate-based coordination polymers (POMCPs), formulated as H3[CuI 3(L)3]2[PM12O40]·xH2O (M = Mo, x = 4 for 1; M = W, x = 6 for 2; and HL = 4-(1H-tetazol-5-yl)pyridine), are prepared by a mineralizer-assisted one-step synthesis strategy and explored as heterogeneous catalysts for p-BQs synthesis. Both compounds have been characterized through elemental analysis, EDS analysis, infrared spectroscopy, UV–vis diffuse reflectance spectrum, EPR, XPS, BET, single-crystal, and powder X-ray diffraction. Single-crystal X-ray diffraction analysis indicates that both 1 and 2 exhibit an interesting 2D sheet structure composed of 2-connected Keggin type anions [PM12O40]3– and hexa-nuclear {CuI 6(HL)6} cluster-based metal–organic chains via Cu···O interactions. When used as catalysts, POMCPs 1 and 2 have excellent catalytic activities in the selective oxidation of substituted phenols to p-BQs with H2O2. Notedly, in the model reaction from 2,3,6-trimethylphenol (TMP) to the vitamin E key intermediate trimethyl-p-benzoquinone (TMBQ), the catalytic activities expressed by turnover frequency (TOF) of 1 and 2 can reach an unprecedented 2400 and 2000 h–1, respectively, at close to 100% TMBQ yield. The truly heterogeneous nature, stability, and structural integrity of both catalysts were ascertained by FTIR, PXRD techniques, and the following cycles. Mechanism studies reveal that both catalysts can involve a dual reaction pathway through a heterolytic oxygen atom transfer mechanism and homolytic radical mechanism. Moreover, the 2D POMCPs with highly accessible bilateral active sites and efficient mass transfer efficiency possess superior catalytic performance to their analogous 3D species.

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Titania-heteropolyacid composites (TiO2-HPA) as catalyst for the green oxidation of trimethylphenol to 2,3,5-trimethyl-p-benzoquinone

Cited by 9 publications

References 38 publications

Kinetics for the biodiesel production from lauric acid over Keggin heteropolyacid loaded in silica framework

Kinetics for the biodiesel production from lauric acid over Keggin heteropolyacid loaded in silica framework

Highly Efficient Supramolecular Catalysts Assembled by Dawson-Type POMs and Metal–Organic Complexes for the Synergistic Catalytic Synthesis of p-Benzoquinones

Highly Efficient Synthesis of p-Benzoquinones Catalyzed by Robust Two-Dimensional POM-Based Coordination Polymers

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