Казанский (Приволжский) федеральный университет, КФУ
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ФЕДЕРАЛЬНЫЙ УНИВЕРСИТЕТ
 
TRANSFORMATION OF THE ACTIVE COMPONENT DURING OXIDATIVE AND REDUCTIVE ACTIVATION OF THE PALLADIUM HYDROGENATION CATALYST
Форма представленияСтатьи в зарубежных журналах и сборниках
Год публикации2020
Языканглийский
  • Ильясов Ильдар Равилевич, автор
  • Ламберов Александр Адольфович, автор
  • Ласкин Артем Игоревич, автор
  • Библиографическое описание на языке оригинала Laskin A. Transformation of the active component during oxidative and reductive activation of the palladium hydrogenation catalyst / Laskin A., Il'Yasov I., Lamberov A. // New Journal of Chemistry. - 2020. - 44. p. 1719-1732.
    Аннотация Palladium catalysts supported on aluminium oxide with acetate and acetylacetonate as precursors were synthesized. The properties of palladium in Pd(Ac)2/(δ+ϰ)-Al2O3 and Pd(Acac)2/(δ+ϰ)-Al2O3 systems treated in oxidizing and reducing atmospheres in a wide temperature range of 300 - 700 ? C were investigated. According to the results of UV-vis/DR and TPR the Pd(Ac)2/(δ+ϰ)-Al2O3 systems oxidized at 300 - 700 ? C are characterized by the presence of large particles of PdO и Pd2+ in the structure of aluminate phases. The subsequent reduction at 500 ? С of pre-oxidized Pd(Ac)2/(δ+ϰ)-Al2O3 systems according to the TEM results is accompanied by the formation of large palladium particles with D = 4.0–4.5 nm and small particles with D = 1.1 nm. At the same time, palladium particles with a diameter of more than 4.0 nm are characterized by the presence of a hydride form of hydrogen. The oxidation of Pd(Acac)2/(δ+ϰ)-Al2O3 in the temperature range of 300-700 ? C leads to the formation of small clusters of PdO and palladium-aluminate phases of non-stoichiometric composition. When reducing, only cluster forms of palladium with D = 1.3 - 1.5 nm are formed from them. At the same time, according to the IRS data, Pd(Ac)2/(δ+ϰ)-Al2O3 catalysts oxidized and reduced at 500 ? C are characterized by a larger number of active centers with a bridge coordination of CO, compared to the Pd(Acac)2/(δ+ϰ)-Al2O3 system. This fact combined with the presence of catalysts of the hydride form of hydrogen for Pd(Ac)2/(δ+ϰ)-Al2O3 leads to a high conversion of methylacetylene and propadiene, but to a low selectivity of their conversion to propylene. An increase in the temperature of the sequential oxidative reduction treatments of Pd(Ac)2/(δ+ϰ)-Al2O3 and Pd(Acac)2/(δ+ϰ)-Al2O3 systems to 600 ? C is accompanied by an increase in the particle size of palladium and the number of atoms with the terminal coordinates of CO molecules. This leads to a significant increase in the conversion of methylacetylene and propadiene.
    Ключевые слова palladium catalyst, selective hydrogenation
    Название журнала NEW JOURNAL OF CHEMISTRY
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