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Diffusional effects in wetproofed catalysts for isotopic exchange between hydrogen gas and water vapour
Author(s) -
Suppiah S.,
Chuang K. T.,
Rolston J. H.
Publication year - 1987
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.5450650210
Subject(s) - catalysis , adsorption , water vapor , hydrogen , diffusion , carbon fibers , deuterium , chemistry , chemical engineering , kinetics , activation energy , surface diffusion , activated carbon , materials science , composite material , thermodynamics , organic chemistry , physics , quantum mechanics , composite number , engineering
Deuterium transfer rates between water vapour and hydrogen gas have been obtained for platinized carbon powder (Pt‐C) and Teflon wetproofed platinized carbon films. The pore diffusional resistance in the catalyst films was assessed by calculating the effectiveness factor, ϵ, from a mathematical model for simultaneous diffusion and first order reversible reaction kinetics. Wetproofing the Pt‐C catalyst with Teflon increased the intrinsic rate of reaction, but the effectiveness factor decreased with increasing catalyst layer thickness. Pore size and surface area distributions and water vapour adsorption isotherms of the Pt‐C/Teflon catalyst films were similar to those of the Pt‐C itself. Since Teflon had negligibly small surface area and very large pores compared to the carbon support, wetproofing did not cause significant changes to the physical characteristics of the platinized carbon.