Theoretical approach to faradaic admittance of hydrogen absorption reaction on metal membrane electrode

✍ Scribed by Chan Lim; Su-Il Pyun

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 615 KB
• Volume: 38
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(93)85082-a

✦ Synopsis

Ahstrati-Faradaic admittance of hydrogen absorption reaction (/err) on metal membrane electrode has been derived on the basis of "two models" of the hm under the permeable boundary condition by using an extension of Armstrong's kinetic approach. In the case of the /tar through adsorbed phase (model A), two limiting cases of the Faradaic admittance are considered depending upon the magnitude of rate of hydrogen transfer from bulk to metal surface. One involves the diffusion-controlled /tar for fast rate of hydrogen transfer and the other is the interfacecontrolled hm for slow rate of hydrogen transfer from bulk to metal surface. Depressing and/or tailing of the second semicircle, often found in the complexplane impedance spectra for hydrogen evolution reaction (her), is fairly explained by the diffusioncontrolled her. In the case of the direct her without passing through the adsorbed phase (model B), the Farad& admittance is differentiated by the absence of adsorption capacitance from that based upon the model A.