Title of Paper:Comparison of Pt and Pd catalysts for hydrogen pump separation from reformate

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Date of Publication:2012-11-15

Journal:JOURNAL OF POWER SOURCES

Included Journals:SCIE、EI、Scopus

Volume:218

Page Number:424-434

ISSN No.:0378-7753

Key Words:Hydrogen purification; Electrochemical separations; Electrocatalyst coated membranes

Abstract:Hydrogen recovery from CO2/H-2 reformate mixtures by selective electrochemical pumping was compared from carbon supported Pt and Pd catalysts. Catalyst coated membranes were prepared by air-brushing a suspension of commercially available 20 wt% Pt/C or 20 wt% Pd/C catalysts and solubilized Nafion in methanol onto Nafion 115 membranes. Electrochemical activity and separation efficiency for the different catalyst layer formulations were evaluated by cyclic voltammetry, polarization and potentiostatic hydrogen pumping. The effective membrane-electrode-assembly (MEA) resistance increased due to dilution of H-2 by CO2; the effective MEA resistance was greater for Pd/C catalysts than for Pt/C catalysts. CO2 adsorbed more strongly to Pd catalysts than Pt catalysts reducing the electrochemical active surface area available for hydrogen oxidation/reduction. Pd/C catalysts had an energy efficiency for hydrogen recovery from reformate mixtures approximately 80% that of Pt catalysts. Because Pd is ten times less costly than Pt the results presented here suggest that Pd/C catalysts would be a promising candidate for hydrogen pumps to recover H-2 from reformate mixtures. (C) 2012 Elsevier B.V. All rights reserved.