Catalysis of methyl viologen radical reactions by polymer-stabilized gold sols. [Gamma radiation]

Journal Article · Thu Jan 22 04:00:00 EST 1981 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j150602a015· OSTI ID:6644734

Meisel, D; Mulac, W A; Matheson, M S

The catalysis of methyl viologen radical cation (MV/sup +/.) decay reactions by gold sol, stabilized by either poly(vinyl sulfate) (PVS) or poly(vinyl alcohol) (PVA), was studied by pulse radiolysis. Stabilization of the sol by PVS eliminates the hydrogen evolution reaction as a pathway for MV/sup +/. decay. This is shown to be due to dimerization of MV/sup +/. (to the biradical) in the potential field of the polyelectrolyte. On PVA-stabilized sols, the hydrogen evolution reaction is a major pathway although side reactions (probably hydrogenation) interfere to a large extent. The rate of adsorption of MV/sup +/. on PVA-stabilized sol is controlled by the diffusion of MV/sup +/. to the gold particle. Subsequent reactions of protonation and electrochemical desorption, (Au)/sub c/sup n//sup -/H/sub m/ + H/sub 3/O/sup +/ ..-->.. (Au)/sub c//sup (n-1)-/H/sub m-1/ + H/sub 2/ + H/sub 2/O, on a slower time scale are the rate-determining steps at the pH range and catalyst concentration used. At higher catalyst concentrations interparticle reaction is invoked to explain the dependence on (Au).

• Research Organization: Argonne National Lab., IL
• OSTI ID: 6644734
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 85:2; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400600* -- Radiation Chemistry
ALCOHOLS
AZINES
BIPYRIDINES
CATALYTIC EFFECTS
CATIONS
CHARGED PARTICLES
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHEMISTRY
COLLOIDS
DECOMPOSITION
DIFFUSION
DIMERIZATION
DISPERSIONS
ELEMENTS
GOLD
HETEROCYCLIC COMPOUNDS
HYDROGEN PRODUCTION
HYDROXY COMPOUNDS
IONS
IRRADIATION
KINETICS
METALS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC POLYMERS
PH VALUE
POLYMERIZATION
POLYMERS
POLYVINYLS
PULSED IRRADIATION
PVA
PYRIDINES
RADIATION CHEMISTRY
RADIATION EFFECTS
RADICALS
RADIOLYSIS
REACTION KINETICS
SOLS
TRANSITION ELEMENTS