KFU. Card publication. Transformation of the active component during oxidative and reductive activation of the palladium hydrogenation catalyst

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TRANSFORMATION OF THE ACTIVE COMPONENT DURING OXIDATIVE AND REDUCTIVE ACTIVATION OF THE PALLADIUM HYDROGENATION CATALYST

Form of presentation

Articles in international journals and collections

Year of publication

2020

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Authors, employees of KFU

Ilyasov Ildar Ravilevich, author

Lamberov Aleksandr Adolfovich, author

Laskin Artem Igorevich, author

Bibliographic description in the original language

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.

Annotation

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 � Pd2+ in the structure of aluminate phases. The subsequent reduction at 500 ? � 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.

Keywords

palladium catalyst, selective hydrogenation

The name of the journal

NEW JOURNAL OF CHEMISTRY

Please use this ID to quote from or refer to the card

https://repository.kpfu.ru/eng/?p_id=235830&p_lang=2

Full metadata record

Field DC	Value	Language
dc.contributor.author	Ilyasov Ildar Ravilevich	ru_RU
dc.contributor.author	Lamberov Aleksandr Adolfovich	ru_RU
dc.contributor.author	Laskin Artem Igorevich	ru_RU
dc.date.accessioned	2020-01-01T00:00:00Z	ru_RU
dc.date.available	2020-01-01T00:00:00Z	ru_RU
dc.date.issued	2020	ru_RU
dc.identifier.citation	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.	ru_RU
dc.identifier.uri	https://repository.kpfu.ru/eng/?p_id=235830&p_lang=2	ru_RU
dc.description.abstract	NEW JOURNAL OF CHEMISTRY	ru_RU
dc.description.abstract	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 � Pd2+ in the structure of aluminate phases. The subsequent reduction at 500 ? � 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.	ru_RU
dc.language.iso	ru	ru_RU
dc.subject	palladium catalyst	ru_RU
dc.subject	selective hydrogenation	ru_RU
dc.title	Transformation of the active component during oxidative and reductive activation of the palladium hydrogenation catalyst	ru_RU
dc.type	Articles in international journals and collections	ru_RU