Ethanol oxidation on electrocatalysts obtained by spontaneous deposition of palladium onto nickel-zinc materials.
Ni-Zn and Ni-Zn-P alloys supported on Vulcan XC-72 are effective materials for the spontaneous deposition of palladium through redox transmetalation with Pd(IV) salts. The materials obtained, Pd-(Ni-Zn)/C and Pd-(Ni-Zn-P)/C, have been characterized by a variety of techniques. The analytical and spectroscopic data show that the surface of Pd-(Ni-Zn)/C and Pd-(Ni-Zn-P)/C contain very small, highly dispersed, and highly crystalline palladium clusters as well as single palladium sites, likely stabilized by interaction with oxygen atoms from Ni--O moieties. As a reference material, a nanostructured Pd/C material was prepared by reduction of an aqueous solution of PdCl(2)/HCl with ethylene glycol in the presence of Vulcan XC-72. In Pd/C, the Pd particles are larger, less dispersed, and much less crystalline. Glassy carbon electrodes coated with the Pd-(Ni-Zn)/C and Pd-(Ni-Zn-P)/C materials, containing very low Pd loadings (22-25 microg cm(-2)), were studied for the oxidation of ethanol in alkaline media in half cells and provided excellent results in terms of both specific current (as high as 3600 A g(Pd)(-1) at room temperature) and onset potential (as low as -0.6 V vs Ag/AgCl/KCl(sat)).
Bambagioni
Valentina
V
Istituto di Chimica dei Composti Organometallici CNR, Sesto Fiorentino, Italy.
Bianchini
Claudio
C
Filippi
Jonathan
J
Oberhauser
Werner
W
Marchionni
Andrea
A
Vizza
Francesco
F
Psaro
Rinaldo
R
Sordelli
Laura
L
Foresti
Maria Luisa
ML
Innocenti
Massimo
M
D000042:Absorption; D000497:Alloys / Q000737:chemistry*; D001674:Bioelectric Energy Sources; D002384:Catalysis; D004563:Electrochemistry; D004566:Electrodes; D000431:Ethanol / Q000737:chemistry*; D006878:Hydroxides / Q000737:chemistry; D009532:Nickel / Q000737:chemistry*; D010084:Oxidation-Reduction; D010165:Palladium / Q000737:chemistry*; D017680:Potassium Compounds / Q000737:chemistry; D013057:Spectrum Analysis; D014961:X-Ray Diffraction; D015032:Zinc / Q000737:chemistry*
D000497:Alloys; D006878:Hydroxides; D017680:Potassium Compounds; D000431:Ethanol; D010165:Palladium; D009532:Nickel; D015032:Zinc; C029943:potassium hydroxide