2024-03-28T09:01:53Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/1885712019-09-27T10:55:27Zcom_10261_101com_10261_5col_10261_480
The role of electron localization in the catalytic function of cerium-oxide-based systems
Ganduglia-Pirovano, M. V.
López-Durán, David
Carrasco Rodríguez, Javier
Fernández Torre, Delia
Pérez, Rubén
Trabajo presentado en el 50th Symposium on Theoretical Chemistry, celebrado en Viena (Austria) del 14 al 18 de septiembre de 2014.
Cerium oxide (Ce02, ceria) surfaces are important for ma ny appl ications, particula rly catalysis. The importance relies to a large extent on its facile reducibility and the associated ability to release lattice oxygen. On removing an O atom, two electrons are left behind that form two reduced Ce3+ species. The electrons occupy split-off states of the initially empty Ce 4f band, Jying inside the 02p-Ce5d band gap of ceria and bei ng highly localized in space [l ]. In this work, we apply density-functional theory (DFT) with the DFT+U approach and show that the ability of ceria to stabilize reduced states is at the origin of the unexpected cata lytic activity of ceria-based systems such as ceria surfaces for the conversion of alkynes to olefins [2], and of ceria supported Ni nanoparticl es for H2 production [3]. DFT simulations of acetylene hydrogenat ion on Ce02(1 l l ) provide molecular-leve! insight into the active site and reaction mechanism, where the formation of highly reactive C2H2 radical species is found to be essential [4], and help rationalize the applicabi l ity of Ce02 as a catalyst for olefi n production. Theoretical Ni/Ce02(l l l) model catalysts revea!strong Ni-ceria interactions -leading to Ni2+ and Ce3 species- as the key factor responsible of a not too weaken C-0 bond upon CO adsorption and a low H20 dissociation barrier , both making the Ni/Ce0 2 system attractive for the production of hydrogen vía the water gas shift (CO+H20C02+H2) reaction .
Peer Reviewed
2019-08-20T09:37:39Z
2019-08-20T09:37:39Z
2014-09-14
2019-08-20T09:37:39Z
comunicación de congreso
http://purl.org/coar/resource_type/c_5794
50th Symposium on Theoretical Chemistry (2014)
http://hdl.handle.net/10261/188571
Sí
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