Механизмы формирования на пористых носителях комплексов d-металлов и их каталитическая активность в редокс-реакциях
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Дата
2015
Науковий керівник
Укладач
Редактор
Назва журналу
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Номер E-ISSN
Назва тому
Видавець
Одеський національний університет імені І. І. Мечникова
Анотація
В обзоре обобщены работы авторов в области создания закрепленных на пористых носителях различного происхождения металлокомплексных катализаторов редокс-
реакций с участием фосфина, монооксида углерода, озона и диоксида серы. Проанализированы факторы, влияющие на механизм формирования и состав поверхностных комплексов, а также их каталитическую активность.
В огляді узагальнено праці авторів в галузі створення закріплених на пористих носіях різного походження металокомплексних каталізаторів редокс-реакцій за участю фосфіну, монооксиду вуглецю, озону та діоксиду сірки. Проаналізовано фактори, що впливають на механізм формування та склад поверхневих комплексів, а також їх каталітичну активність.
The catalytic activity of supported complexes of d metals in redox reactions with participation of gaseous toxicants, PH3, CO, O3, and SO2, depends on their composition. Owing to the variety of physicochemical and structural-adsorption properties of available supports, their influence on complex formation processes, the composition and catalytic activity of metal complexes anchored on them varies over a wide range. The metal complex formation on supports with weak ionexchanging properties is similar to that in aqueous solutions. In this case, the support role mainly adds up to the ability to reduce the activity of water adsorbed on them. The interaction between a metal complex and a support surface occurs through adsorbed water molecules. Such supports can also aff ect complex formation processes owing to protolytic reactions on account of acidic properties of sorbents used as supports. The catalytic activity of metal complexes supported on polyphase natural sorbents considerably depends on their phase relationship. In the case of supports with the nonsimple structure and pronounced ionexchanging properties, for instance, zeolites and laminar silicates, it is necessary to take into account the variety of places where metal ions can be located. Such location places determine distinctions in the coordination environment of the metal ions and the strength of their bonding with surface adsorption sites and, therefore, the catalytic activity of surface complexes formed by theses metal ions. Because of the energy surface inhomogeneity, it is important to determine a relationship between the strength of a metal complex bonding with a support surface and its catalytic activity. For example, bimetallic complexes are catalytically active in the reactions of oxidation of the above gaseous toxicants. In particular, in the case of carbon monoxide oxidation, the most catalytic activity is shown by palladium-copper complexes in which copper(II) is strongly fixed on a support surface as a result of the ion exchanging and palladium(II) is bound with copper(II) through a water molecule or some other ligands. The formation of surface complexes can occur as a result of the covalent binding of 3d metals with ligands preliminarily immobilized on supports. However, the examined complexes with aerosol immobilized Schiff bases are catalytically active only in the reaction of ozone decomposition.
В огляді узагальнено праці авторів в галузі створення закріплених на пористих носіях різного походження металокомплексних каталізаторів редокс-реакцій за участю фосфіну, монооксиду вуглецю, озону та діоксиду сірки. Проаналізовано фактори, що впливають на механізм формування та склад поверхневих комплексів, а також їх каталітичну активність.
The catalytic activity of supported complexes of d metals in redox reactions with participation of gaseous toxicants, PH3, CO, O3, and SO2, depends on their composition. Owing to the variety of physicochemical and structural-adsorption properties of available supports, their influence on complex formation processes, the composition and catalytic activity of metal complexes anchored on them varies over a wide range. The metal complex formation on supports with weak ionexchanging properties is similar to that in aqueous solutions. In this case, the support role mainly adds up to the ability to reduce the activity of water adsorbed on them. The interaction between a metal complex and a support surface occurs through adsorbed water molecules. Such supports can also aff ect complex formation processes owing to protolytic reactions on account of acidic properties of sorbents used as supports. The catalytic activity of metal complexes supported on polyphase natural sorbents considerably depends on their phase relationship. In the case of supports with the nonsimple structure and pronounced ionexchanging properties, for instance, zeolites and laminar silicates, it is necessary to take into account the variety of places where metal ions can be located. Such location places determine distinctions in the coordination environment of the metal ions and the strength of their bonding with surface adsorption sites and, therefore, the catalytic activity of surface complexes formed by theses metal ions. Because of the energy surface inhomogeneity, it is important to determine a relationship between the strength of a metal complex bonding with a support surface and its catalytic activity. For example, bimetallic complexes are catalytically active in the reactions of oxidation of the above gaseous toxicants. In particular, in the case of carbon monoxide oxidation, the most catalytic activity is shown by palladium-copper complexes in which copper(II) is strongly fixed on a support surface as a result of the ion exchanging and palladium(II) is bound with copper(II) through a water molecule or some other ligands. The formation of surface complexes can occur as a result of the covalent binding of 3d metals with ligands preliminarily immobilized on supports. However, the examined complexes with aerosol immobilized Schiff bases are catalytically active only in the reaction of ozone decomposition.
Опис
Вісник Одеського нац. університету: сер.: Хімія : науковий журнал / ОНУ ім. І.І. Мечникова . – Одеса : ОНУ ім. І.І. Мечникова, 2015
Ключові слова
монооксид углерода, фосфин, озон, диоксид серы, низкотемпературные редокс-реакции, нанесенные металлокомплексные катализаторы, монооксид вуглецю, фосфін, діоксид сірки, низькотемпературні редокс-реакції, нанесені металокомплексні каталізатори, carbon monoxide, phosphine, ozone, sulfur dioxide, redox reactions, supported metal-complex catalysts
Бібліографічний опис
Вісник Одеського національного університету = Odesa National University Herald