How to Reach 100% Selectivity in H2O2-Based Oxidation of 2,3,6-Trimethylphenol to Trimethyl-p-Benzoquinone over Ti,Si-Catalysts Full article
| Conference |
8th European Workshop Meeting on Selective Oxidation 26-31 Aug 2007 , Turku |
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| Journal |
Catalysis Today
ISSN: 0920-5861 , E-ISSN: 1873-4308 |
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| Output data | Year: 2009, Volume: 141, Number: 3-4, Pages: 330-336 Pages count : 7 DOI: 10.1016/j.cattod.2008.06.005 | ||||
| Tags | 2,3,6-Trimethylphenol, Hydrogen peroxide, Selective oxidation, Titanium-silicate catalysts, Trimethylbenzoquinone | ||||
| Authors |
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| Affiliations |
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Funding (2)
| 1 | National Research Council | 30212 |
| 2 | National Research Council | 50558 |
Abstract:
A comprehensive study of structure/activity/selectivity relationships and mechanistic aspects of the oxidation of 2,3,6-trimethylphenol (TMP) with aqueous H2O2 over a wide variety of titanium-silicate catalysts allowed us to infer requirements to an optimal catalyst and optimal reaction conditions for this reaction and to produce 2,3,5-trimethyl-1,4-benzoquinone (TMBQ, Vitamin E precursor) with nearly 100% selectivity at 100% substrate conversion. The main by-products in the TMP oxidation are C–C and C–O dimers, formed by coupling of intermediate phenoxyl radicals. The formation of TMBQ is favoured by (1) a poor coordinating solvent (MeCN), (2) elevated temperature (80 °C), (3) low TMP concentration (not higher than 0.1 M), (4) high H2O2/TMP molar ratio (ca. 3.5), and (5) low TMP/Ti ratio (<10–20). The crucial factors which determine the selectivity of Ti,Si-catalysts in TMP oxidation to TMBQ are mesoporosity and an optimal surface concentration (ca. 0.7–1.0 Ti atoms/nm2) of accessible highly dispersed, probably, dimeric Ti(IV) species. The catalysts prepared by a simple, affordable and cheap synthesis methodology via grafting titanium(IV) precursors onto the surface of commercial mesoporous silica completely fulfil these requirements and thus can be viewed as promising catalysts for environmentally benign TMBQ production.
Cite:
Kholdeeva O.A.
, Ivanchikova I.D.
, Guidotti M.
, Ravasio N.
, Sgobba M.
, Barmatova M.V.
How to Reach 100% Selectivity in H2O2-Based Oxidation of 2,3,6-Trimethylphenol to Trimethyl-p-Benzoquinone over Ti,Si-Catalysts
Catalysis Today. 2009. V.141. N3-4. P.330-336. DOI: 10.1016/j.cattod.2008.06.005 WOS Scopus РИНЦ ANCAN OpenAlex
How to Reach 100% Selectivity in H2O2-Based Oxidation of 2,3,6-Trimethylphenol to Trimethyl-p-Benzoquinone over Ti,Si-Catalysts
Catalysis Today. 2009. V.141. N3-4. P.330-336. DOI: 10.1016/j.cattod.2008.06.005 WOS Scopus РИНЦ ANCAN OpenAlex
Dates:
| Published online: | Jul 16, 2008 |
| Published print: | Mar 30, 2009 |
Identifiers:
| Web of science: | WOS:000264816500015 |
| Scopus: | 2-s2.0-60949092018 |
| Elibrary: | 13612838 |
| Chemical Abstracts: | 2009:252045 |
| Chemical Abstracts (print): | 150:474834 |
| OpenAlex: | W1979861373 |