Mass-transport properties of electrosprayed Pt/C catalyst layers for polymer-electrolyte fuel cells

JOURNAL OF POWER SOURCES

卷:427

Article

Conde, Julio J.¹  Antonia Folgado, M.¹  Ferreira-Aparicio, P.¹  Chaparro, Antonio M.¹  Chowdhury, Anamika²  Kusoglu, Ahmet²  Cullen, David³  Weber, Adam Z.² 

[1] CIEMAT, Dept Energy, Avda Complutense 40, E-28040 Madrid, Spain

[2] Lawrence Berkeley Natl Lab, Energy Convers Grp, Energy Technol Area, 1 Cyclotron Rd, Berkeley, CA 94720 USA

[3] Oak Ridge Natl Lab, Ctr Nanophase Mat Sci, Oak Ridge, TN 37831 USA

关键词: PEMFC;    Catalyst layer;    Electrospray;    Mass transport;    Water uptake;    Thin porous film;   

DOI  :  10.1016/j.jpowsour.2019.04.079

来源: Elsevier

【 摘 要 】

Mass-transport properties of electrosprayed catalyst-layers based on Pt/C and ionomer (Nafion) are studied with hydrogen limiting-current technique, water-vapor-uptake, scanning transmission microscopy (STEM), single-cell testing, and impedance spectroscopy. The hydrogen limiting-current technique provides the transport resistance of the layers (R-CL(mt)), which shows to be lower in electrosprayed layers compared with conventional layers, especially at very low platinum loadings (0.025 mg(pt).cm(-2)) and low cell temperature, denoting superior mass-transport properties. Images of the distribution of Pt, F, and C elements reveal the ionomer preferentially interacting with the Pt nanoparticles. Water-vapor-uptake experiments show larger vapor absorption for electrosprayed than conventional catalyst layers. Such large water-vapor uptake capability is combined with superhydrophobicity, ie. very low interaction with water in liquid phase (wettability). Both apparently contradictory properties result from a particular configuration of the amphiphilic ionomer in the electrosprayed layers, and provide ideal conditions for high mass transport and ionic conductivity in a catalyst layer. Electrosprayed layers as cathode catalyst layers show peak response at a loading of 0.17 mg(p)(t).cm(-2) (18 mu m layer thickness when using Pt/C 20 wt% catalyst) where they provide minimal mass-transport and polarization resistances.

【 授权许可】

Free