Abstract
A new hydrodynamic model for two-phase water-electrolysis filtration in porous electrocatalysts and current collectors using a solid polymer electrolyte has been developed. The model takes into account the effect due to the internal structure of the porous elements on gas-liquid distribution and transport and electrochemical characteristics. Owing to the finite hydrodynamic permeability of porous elements, a limiting mass-exchange current was shown to set in, with the voltage tending to infinity because of the electrolyte depletion within the electrochemical reaction zone. The efficiency of the porous current collectors of various types has been considered under specified process conditions using computational modelling.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Abbreviations
- C 0 :
-
water density (55.5×103 mol m−3)
- d :
-
gas-liquid meniscus diameter, or pore diameter (m)
- d bd :
-
boundary pore diameter, model parameter (m)
- F :
-
Faraday's constant (96487 C mol−1)
- H :
-
vapour pressure (Pa)
- i :
-
reaction current density (A m−2)
- i 0 :
-
exchange current density (A m−2)
- J :
-
total current density (A m−2)
- K :
-
effective permeability of porous layers (m2)
- K m :
-
membrane hydraulic permeability (Pa−1 m s−1)
- l :
-
porous layer thickness (m)
- l m :
-
membrane thickness (m)
- N 0 :
-
membrane water-flow rate (mol m−2 s−1)
- n :
-
membrane H2O/H+ molar flow ratio
- P :
-
porous layer pressure (Pa)
- P br :
-
gas breakdown porous-layer pressure (Pa)
- R :
-
gas constant (8.314 J mol−1 K−1)
- S :
-
inner specific surface per unit volume of layer (m−1)
- T :
-
temperature (K)
- U :
-
cell voltage (V)
- x :
-
coordinate for anodic part of cell (m)
- y :
-
coordinate for cathodic part of cell (m)
- ε:
-
porosity (fraction of unity)
- η:
-
dynamic viscosity (Pa s)
- K 0 :
-
solution conductivity within pores of reaction layer (Ω−1 m−1)
- K m :
-
membrane conductivity (Ω−1 m−1)
- μ:
-
electrochemical potential (J mol−1)
- σ:
-
surface gas-liquid surface tension (N m−1)
- Φ:
-
surface overpotential for reaction (V)
- g :
-
gas
- l:
-
liquid
- bd:
-
boundary
- br:
-
gas breakdown
- m:
-
membrane
- a:
-
anode
- c:
-
cathode
- i :
-
1 catalytic layer
- i :
-
2 current collector
References
USA Patent No. 4 546 010 (1985).
L. I. Kheifets and A. B. Goldberg,Elektrokhimiya 25 (1989) 3.
‘Synthetic Membranes: Science, Engineering and Applications, Proceedings of the NATO Advanced Study Institute) (edited by P. M. Bungay, H. K. Lonsdale and M. N. Pinko), D. Reidel, Dordrecht (1986) 733 pp.
U. M. Vol'fkovich, N. V. Kuleshov, and E. L. Philippov,Elektrokhimiya 16 (1980) 1512.
L. I. Kheifets and A. B. Goldberg,Teor. Osnovy Khim. Tekhnol. (TOKhT) 16 (1982) 627.
L. I. Kheifets and A. V. Neimark, ‘Mnogofaznye protsessy v poristykh sredakh’ (‘Multiphase processes in porous media’), Khimiya, Moscow (1982) 320 pp.
R. B. McMullin and G. A. Muccini,AIChE Journal 9 (1956) 393.
A. A. Vedenyapin, A. Yu. Krylova, A. G. Gazaryan, T. I. Kuznetsova, O. A. Malykh, G. I. Emel'yanova, A. L. Lapidus, and S. V. Yushin,Elektrokhimiya 27 (1991) 848.
J. S. Newman, ‘Electrochemical Systems’, Prentice Hall, Englewood Cliffs, NJ (1973) 432 pp.
R. B. McMullin,J. Electrochem. Soc. 116 (1969) 416.
L. M. Pisman,Chem. Eng. Sci. 31 (1976) 693.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Goldberg, A.B., Kheifets, L.I., Vaganov, A.G. et al. A hydrodynamic model for water decomposition in electrolyzers with a solid polymer electrolyte. J Appl Electrochem 22, 1147–1154 (1992). https://doi.org/10.1007/BF01297416
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF01297416