Dynamics of the Activity and Physicochemical Characteristics of Pt/WO4 2−–ZrO2 Catalysts in the Hydroisomerization of Heptane and Heptane–Benzene Mixtures : научное издание

Описание

Тип публикации: статья из журнала

Год издания: 2017

Идентификатор DOI: 10.1007/s10562-017-1980-1

Ключевые слова: benzene, Carbonaceous deposits, deactivation, Heptane, hydroisomerization, Tungstated zirconia catalyst

Аннотация: The dynamics of the activity and selectivity of bifunctional platinum tungstated zirconia PtWZ catalyst in the hydroisomerization of n-heptane and heptane–benzene mixture is discussed in the paper. The change in the properties of the catalyst before and after reaction were characterized using different techniques. The catalyst showПоказать полностьюed high efficiency for the hydroisomerization of heptane and heptane–benzene mixture, however, deactivation occurred with time on stream, more significantly when benzene was present in the reaction mixture. The carbonaceous matter was deposited on the catalyst (up to 0.8%) during the hydroisomerization reaction. Predominantly aliphatic carbonaceous «poly-CxHy» species, much less oxidized and little aromatic «graphite-like» species were identified by XPS spectra on the catalyst after the heptane isomerization. In the presence of benzene, the formation of «graphite-like» matter increased progressively as temperature increased. However, no appreciable changes in the bulk properties of the t-ZrO2 matrix (phase composition, specific surface area, pore volume, pore size distribution) and in the state of platinum component were revealed, though an increased extent of W6+ to W5+ reduction was detected by XPS spectra irrespectively of the reaction conditions. The deactivation of the PtWZ catalyst was suggested to result from the blocking the active centers by carbonaceous deposits, the deactivation of the acidic centers being more pronounced as compared to metallic ones. All the carbonaceous deposits were burned-off completely below 450–500 °C. Graphical Abstract: [Figure not available: see fulltext.]

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Издание

Журнал: Catalysis Letters

Выпуск журнала: Т. 147, 3

Номера страниц: 773-784

ISSN журнала: 1011372X

Издатель: Springer Science+Business Media B.V., Formerly Kluwer Academic Publishers B.V.

Авторы

  • Kuznetsov P.N. (Institute of Chemistry and Chemical Technology SB RAS,Federal Research Center “Krasnoyarsk Science Center SB RAS”)
  • Obukhova A.V. (Institute of Chemistry and Chemical Technology SB RAS,Federal Research Center “Krasnoyarsk Science Center SB RAS”)
  • Kuznetsova L.I. (Institute of Chemistry and Chemical Technology SB RAS,Federal Research Center “Krasnoyarsk Science Center SB RAS”)
  • Mikhlin Y.L. (Institute of Chemistry and Chemical Technology SB RAS,Federal Research Center “Krasnoyarsk Science Center SB RAS”)

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