Deactivation behavior of Pd/C and Pt/C catalysts in the gas-phase hydrodechlorination of chloromethanes: Structure-reactivity relationship

This study analyzes the influence of chemical and physical properties of Pd/C and Pt/C hydrodechlorination (HDC) catalysts in the different evolution of their activity during time on stream. Pt/C showed stable activity in the HDC of dichloromethane (DCM) and chloroform (TCM), while Pd/C was deactiva...

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Detalhes bibliográficos
Autores: Martín Martínez, María, Álvarez-Montero, A., Gómez-Sainero, L.M., Baker, R.T., Palomar, J., Omar, S., Eser, S., Rodriguez, J.J.
Formato: artículo
Fecha de publicación:2015
País:España
Recursos:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/107231
Acesso em linha:https://hdl.handle.net/20.500.14352/107231
Access Level:acceso abierto
Palavra-chave:66
544.47
Hydrodechlorination
Chloromethanes
Deactivation
Pd/C
Pt/C
Ingeniería química
3303 Ingeniería y Tecnología Químicas
3303.01 Tecnología de la Catálisis
Descrição
Resumo:This study analyzes the influence of chemical and physical properties of Pd/C and Pt/C hydrodechlorination (HDC) catalysts in the different evolution of their activity during time on stream. Pt/C showed stable activity in the HDC of dichloromethane (DCM) and chloroform (TCM), while Pd/C was deactivated after 90h of operation, particularly during HDC of DCM. The deactivation of Pd/C catalyst can be attributed to the lower proportion of zero-valent species and larger metal particle size. This appears to hinder the H2 dissociation, enhance the irreversible chemisorption of reactants and reaction products, and favor coupling reactions (leading to the formation of carbonaceous deposits) and/or metal phase change reactions. The more extensive deactivation of Pd/C in the HDC of DCM is attributed to the stronger chemisorption of the reactant on the catalyst, which leads to the formation of a new PdCx phase by the incorporation of carbon atoms into the metal lattice