Non-faradaic electrochemical modification of catalytic activity. 1. The case of ethylene oxidation on Pt

Journal Article · Sat Jul 01 04:00:00 EDT 1989 · Journal of Catalysis; (USA)

DOI:https://doi.org/10.1016/0021-9517(89)90306-0· OSTI ID:7007259

Bebelis, S; Vayenas, C G ^[1]

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1. Univ. of Patras (Greece)

It was found that the catalytic activity of polycrystalline Pt for the oxidation of ethylene to CO{sub 2} and H{sub 2}O can be increased by up to a factor of 50 when oxygen anion O{sup 2{minus}} are electrochemically pumped onto the Pt catalyst surface. The experiments were conducted using a stabilized zirconia solid electrolyte at temperatures of 550 to 725 K. The steady-state increase in the catalytic reaction rate is typically 10{sup 5} higher than the rate of O{sup 2{minus}} transport to the catalyst surface. Over a wide range of conditions the catalytic reaction rate increases exponentially with the catalyst-solid electrolyte overpotential {eta} which is proportional to the change in catalyst work function. The reaction activation energy decreases toward zero with increasing {eta}. The phenomena are completely reversible and show that catalyst work function and catalytic activity can be varied at will by adjusting the catalyst potential. A model which takes into account the change in catalyst work function with changing catalyst activation overpotential and the consequent changes in the bonding strength of chemisorbed species is proposed. The model is in semiquantitative agreement with experiment.

• OSTI ID: 7007259
• Journal Information: Journal of Catalysis; (USA), Journal Name: Journal of Catalysis; (USA) Vol. 118:1; ISSN 0021-9517; ISSN JCTLA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400800* -- Combustion
Pyrolysis
& High-Temperature Chemistry
ACTIVATION ENERGY
ALKENES
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CATALYSIS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL COATING
CHEMICAL REACTIONS
CHEMISORPTION
DEPOSITION
ELECTROCHEMICAL COATING
ELECTROLYTES
ELEMENTS
ENERGY
ETHYLENE
FLUIDS
GASES
HIGH TEMPERATURE
HYDROCARBONS
MATHEMATICAL MODELS
METALS
NONMETALS
ORGANIC COMPOUNDS
OXIDATION
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PLATINUM
PLATINUM METALS
SEPARATION PROCESSES
SOLID ELECTROLYTES
SORPTION
SURFACE COATING
SURFACE PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
VAPORS
WATER VAPOR
ZIRCONIUM COMPOUNDS
ZIRCONIUM OXIDES