ISSN:
1573-8663
Keywords:
heterocontact
;
CO oxidation
;
electric control
;
cupric oxide
;
zinc oxide
Source:
Springer Online Journal Archives 1860-2000
Topics:
Electrical Engineering, Measurement and Control Technology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract The CuO/ZnO heterocontact is made by stacking CuO and ZnO porous ceramics and its catalytic activity for CO oxidation reaction is evaluated as a function of applied bias. Its catalytic activity is strongly depend on the dc applied bias and when the reverse bias (CuO-, ZnO+) is applied to the heterocontact, the amount of the produced \hboxCO2 from the catalytic interface rapidly increases, while it decreases when forward bias is applied. The magnitude of the enhancement of the catalytic activity by reverse applied bias is extremely large (30% for −2.0 V at 320°C), comparing with the results in the gradient composition CuO/ZnO heterocontact. The p-i-n structure is suggested as to the electronic structure of the CuO-ZnO contact interfaces and supposing p-i-n structure, the surface Fermi level position of CuO and ZnO are guessed to move as a function of applied bias. The catalytic reaction over CuO make a large contribute to the whole catalytic reaction at the CuO/ZnO heterocontact and it would be modified by the applied voltage dependent surface Fermi level position of CuO. The working mechanisms of such phenomena are qualitatively discussed by the electronic theory of catalyst proposed by Wolkenstein.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1009910827420
Permalink