de Lucas-Consuegra, A. , Gonzalez-Cobos, J. , Carcelen, V. , Magen, C. , ENDRINO ARMENTEROS, JOSÉ LUIS, Valverde, J. L.
Si
J. Catal.
Article
Científica
6.073
2.553
01/11/2013
000327903900002
2-s2.0-84880908167
This study reports for the first time in the literature that the electrochemical promotion (EPOC) of Pt nanoparticles (of around 3 nm) dispersed on a diamond-like carbon (DLC) matrix. A novel Pt-DLC catalyst film has been prepared by the technique of cathodic arc deposition onto a K-beta Al2O3 solid electrolyte support. The catalyst film has been characterized and tested under EPOC conditions in H-2 production from methanol via partial oxidation (POM) and steam reforming (SRM). After a temperature-programmed pretreatment, the Pt-DLC film achieved a suitable electrical conductivity due to the transition of the sp(3)-hybridized carbon form into a more graphitic structure (sp(2)-hybridized) as supported by different characterization measurements such as STEM and EELS. Under EPOC conditions, the H-2 production rates were increased 2.5 and 3.4 times under optimal promoter coverage for POM and SRM, respectively. In addition, under POM conditions, two different electropromotional states were achieved at two different potentials attributed to the formation of different kinds of promoter phases, as confirmed by cyclic voltammetry. Finally, a comparison of the Pt-DLC catalyst film vs. a pure dense Pt layer prepared by the same technique demonstrated the higher activity of the former, due to the lower size of the Pt nanoparticles supported on the DLC matrix. (C) 2013 Elsevier Inc. All rights reserved.
Electrochemical promotion; NEMCA effect; H-2 production; Partial oxidation; Steam reforming; Diamond-like carbon; Pt-DLC; Cathodic arc deposition; Pt nanoparticles