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

Abstract

Mass-transport properties of electrosprayed catalyst-layers based on Pt/C and ionomer (Nafion) are investigated 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 demonstrates 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 reflect peak response at a loading of 0.17 mg_Pt·cm^-2 (18 μm layer thickness when using Pt/C 20 wt% catalyst) where they provide minimal mass-transport and polarization resistances.

Authors:

Conde, Julio J.  ^[1];

• Search DOE PAGES for author "Conde, Julio J."
• Search DOE PAGES for ORCID "0000-0001-8739-6893"

Folgado, M. Antonia ^[1]; Ferreira-Aparicio, P. ^[1]; Chaparro, Antonio M.  ^[1];

• Search DOE PAGES for author "Chaparro, Antonio M."
• Search DOE PAGES for ORCID "0000-0001-6822-4797"

Chowdhury, Anamika ^[2]; Kusoglu, Ahmet ^[2]; Cullen, David ^[3]; Weber, Adam Z.  ^[2]

• Search DOE PAGES for author "Weber, Adam Z."
• Search DOE PAGES for ORCID "0000-0002-7749-1624"

---

+ Show Author Affiliations

1. Research Centre for Energy, Environment and Technology (CIEMAT), Madrid (Spain)
2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Publication Date:

Wed Jun 12 00:00:00 EDT 2019

Research Org.:

Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Sponsoring Org.:

USDOE Office of Energy Efficiency and Renewable Energy (EERE)

OSTI Identifier:

1531234

Alternate Identifier(s):

OSTI ID: 1564467

Grant/Contract Number:  

AC05-00OR22725

Resource Type:

Accepted Manuscript

Journal Name:

Journal of Power Sources

Additional Journal Information:

Journal Volume: 427; Journal Issue: C; Journal ID: ISSN 0378-7753

Publisher:

Elsevier

Country of Publication:

United States

Language:

English

Subject:

08 HYDROGEN; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; PEMFC; Catalyst layer; Electrospray; Mass transport; Water uptake; Thin porous film