Heteropoly Acid/Carbon Nanotube Hybrid Materials as Efficient Solid‐Acid Catalysts

A prototype supported solid‐acid catalyst composed of a heteropoly acid (HPA) and nitrogen‐functionalized carbon nanotubes (NCNT) has been developed. The chemical structure and acid strength of the HPA/NCNT hybrid have been characterized thoroughly by IR spectroscopy, X‐ray photoelectron spectroscopy, TEM, and titration measurements. NCNT supports provide the HPA with an ideal hydrophobic environment, which could prevent the deactivation of the acid sites effectively in aqueous media. HPA/NCNT hybrid catalysts tend to adsorb and enrich hydrophobic substrates (ester) and release the product with high polarity (ethanol) in the aqueous phase, and this synergistic effect facilitates the catalytic process and enhances the activity of HPAs for ester hydrolysis reactions. The HPA and NCNT combine through electrostatic interactions, which ensures the relatively high stability and easy regeneration of the HPA/NCNT hybrid catalysts. The present approach provides a promising and universal strategy for the construction of hybrid catalysts based on HPA and nanocarbon with unique acidic or redox properties.

[1]  Jian Zhang,et al.  Revealing the enhanced catalytic activity of nitrogen-doped carbon nanotubes for oxidative dehydrogenation of propane. , 2013, Chemical communications.

[2]  S. Ismail-Beigi,et al.  Mechanism for strong binding of CdSe quantum dots to multiwall carbon nanotubes for solar energy harvesting. , 2013, Nanoscale.

[3]  D. Su,et al.  Nanocarbons for the development of advanced catalysts. , 2013, Chemical reviews.

[4]  Tianbo Liu,et al.  Solution behaviors and self-assembly of polyoxometalates as models of macroions and amphiphilic polyoxometalate-organic hybrids as novel surfactants. , 2012, Chemical Society reviews.

[5]  Liang Wang,et al.  Transesterification catalyzed by ionic liquids on superhydrophobic mesoporous polymers: heterogeneous catalysts that are faster than homogeneous catalysts. , 2012, Journal of the American Chemical Society.

[6]  Chenze Qi,et al.  Design and Synthesis of Mesoporous Polymer-Based Solid Acid Catalysts with Excellent Hydrophobicity and Extraordinary Catalytic Activity , 2012 .

[7]  Heng Wang,et al.  Nanohybridization of polyoxometalate clusters and single-wall carbon nanotubes: applications in molecular cluster batteries. , 2011, Angewandte Chemie.

[8]  Xun Wang,et al.  Construction of Amphiphilic Polyoxometalate Mesostructures as a Highly Efficient Desulfurization Catalyst , 2011, Advanced materials.

[9]  Gianfranco Scorrano,et al.  Efficient water oxidation at carbon nanotube-polyoxometalate electrocatalytic interfaces. , 2010, Nature chemistry.

[10]  Bao-hang Han,et al.  Graphene‐Based Nanoporous Materials Assembled by Mediation of Polyoxometalate Nanoparticles , 2010 .

[11]  D. Su,et al.  Tuning the acid/base properties of nanocarbons by functionalization via amination. , 2010, Journal of the American Chemical Society.

[12]  D. Su,et al.  Transesterification of triglycerides using nitrogen-functionalized carbon nanotubes. , 2010, ChemSusChem.

[13]  Lixin Wu,et al.  Surfactant-encapsulated polyoxometalates as immobilized supramolecular catalysts for highly efficient and selective oxidation reactions. , 2010, Chemistry.

[14]  W. Wernsdorfer,et al.  Assembly of a magnetic polyoxometalate on SWNTs. , 2010, Nanoscale.

[15]  Lixin Wu,et al.  Polyoxometalate/polymer hybrid materials: fabrication and properties , 2009 .

[16]  N. R. Shiju,et al.  Cs exchanged phosphotungstic acid as an efficient catalyst for liquid-phase Beckmann rearrangement of oximes , 2009 .

[17]  A. Micek-Ilnicka.  The role of water in the catalysis on solid heteropolyacids , 2009 .

[18]  D. Su,et al.  Amino-functionalized carbon nanotubes as solid basic catalysts for the transesterification of triglycerides. , 2009, Chemical communications.

[19]  E. Iglesia,et al.  Consequences of acid strength for isomerization and elimination catalysis on solid acids. , 2009, Journal of the American Chemical Society.

[20]  Lin Xu,et al.  Toluene alkylation with 1-octene over supported heteropoly acids on MCM-41 catalysts , 2009 .

[21]  Wei Xia,et al.  Surface characterization of oxygen-functionalized multi-walled carbon nanotubes by high-resolution X-ray photoelectron spectroscopy and temperature-programmed desorption , 2007 .

[22]  T. Okuhara,et al.  Water-tolerant, highly active solid acid catalysts composed of the keggin-type polyoxometalate H(3)PW(12)O(40) immobilized in hydrophobic nanospaces of organomodified mesoporous silica. , 2007, Angewandte Chemie.

[23]  Haolong Li,et al.  A Novel, Luminescent, Silica‐Sol–Gel Hybrid Based on Surfactant‐ Encapsulated Polyoxometalates , 2007 .

[24]  Hang Sun,et al.  Onionlike hybrid assemblies based on surfactant-encapsulated polyoxometalates. , 2007, Angewandte Chemie.

[25]  I. Kozhevnikov.  Sustainable Heterogeneous Acid Catalysis by Heteropoly Acids , 2007 .

[26]  K. D. de Jong,et al.  Nitrogen-containing carbon nanotubes as solid base catalysts. , 2006, Chemical communications.

[27]  R. Neumann,et al.  An example of lipophiloselectivity: the preferred oxidation, in water, of hydrophobic 2-alkanols catalyzed by a cross-linked polyethyleneimine-polyoxometalate catalyst assembly. , 2006, Journal of the American Chemical Society.

[28]  Yongxing Yang,et al.  Ultra-deep desulfurization of diesel: oxidation with a recoverable catalyst assembled in emulsion. , 2004, Chemistry.

[29]  James H. Clark,et al.  Solid acids for green chemistry. , 2002, Accounts of chemical research.

[30]  M. Misono,et al.  Catalysis by heteropoly compounds—recent developments , 2001 .

[31]  M. Misono,et al.  Microstructure of Cesium Hydrogen Salts of 12-Tungstophosphoric Acid Relevant to Novel Acid Catalysis† , 2000 .

[32]  W. Hölderich,et al.  Industrial application of solid acid–base catalysts , 1999 .

[33]  T. Ueda,et al.  Synthesis, characterisation and voltammetric study of a β-Keggin-type [PW12O40]3- complex , 1999 .

[34]  T. Nakato,et al.  Water-tolerant solid acid catalysis of Cs2.5H0.5PW12O40 for hydrolysis of esters in the presence of excess water , 1997 .

[35]  N. Essayem,et al.  Ammonia adsorption–desorption over the strongsolid acid catalystH3PW12O40 and itsCs+ and NH4+ saltsComparison with sulfated zirconia , 1997 .

[36]  C. Hill,et al.  Carbon powder and fiber-supported polyoxometalate catalytic materials. Preparation, characterization, and catalytic oxidation of dialkyl sulfides as mustard (HD) analogues , 1996 .

[37]  C. Hill,et al.  Selective Oxidation of Thioether Mustard (HD) Analogs bytert-Butylhydroperoxide Catalyzed by H5PV2Mo10O40Supported on Porous Carbon Materials , 1996 .

[38]  H. A. Levy,et al.  Dodecatungstophosphoric acid hexahydrate, (H5O2+)3(PW12O403−). The true structure of Keggin's `pentahydrate' from single-crystal X-ray and neutron diffraction data , 1977 .