Ta0.3Ti0.7O2 electrocatalyst supports exhibit exceptional electrochemical stability

Amod Kumar; Vijay Ramani

doi:10.1149/2.038311jes

Ta_0.3Ti_0.7O₂ electrocatalyst supports exhibit exceptional electrochemical stability

Amod Kumar
, Vijay Ramani

Research output: Contribution to journal › Article › peer-review

43 Scopus citations

Abstract

Tantalum (Ta) modified TiO₂ was synthesized using a sol-gel procedure and evaluated for use as an electrocatalyst support. Platinumnanoparticles were deposited on this support via the incipient wetness method. X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray energy dispersive spectroscopy (XEDS), X-ray photoelectron spectroscopy (XPS) and nitrogen desorption were used to investigate their microstructure. Of the formulations studied, Ta_0.3Ti_0.7O₂ possessed an adequate powder electronic conductivity of 0.2 S/cm. The capacitance of this Ta_0.3Ti_0.7O₂ support changed by only 12% whereas the pseudocapacitance of a carbon benchmark changed by over 100% over 10,000 support stability test cycles (support stability test protocol: 1.0-1.5 V vs. RHE at a scan rate of 500 mV/s in a 0.1MHClO4 electrolyte at 25?C) under identical test conditions. The stability of 20% Pt/Ta_0.3Ti _0.7O₂, 20% Pt/C, and 46% Pt/C (commercial, TKK) catalysts were evaluated by monitoring the evolution of the electrochemical surface area (ECSA) under load cycling (load cycling protocol: 0.6-0.95 V vs. RHE with a dwell time of 3 s at either potentials in a 0.1 MHClO4 electrolyte at 25?C). The loss in ECSA in 20% Pt/Ta_0.3Ti_0.7O₂ was found to be 35% compared to 44-47% for 20% Pt/C and 46% Pt/C over 10,000 load cycles. 20% Pt/Ta_0.3Ti_0.7O₂ yielded the following performance-related metrics: the ECSA of this electrocatalyst was 41 m2/g, the mass activity and area-specific activities for the oxygen reduction reaction (ORR) determined at 0.9 V vs. RHE in a 0.1 M HClO4 electrolyte at 25?C were 62 mA/mgPt and 151 μA/cm2 Pt, respectively. Koutecky-Levich analysis carried out to evaluate ORR kinetics suggested that all 3 catalysts (20% Pt/Ta _0.3Ti_0.7O₂, 20% Pt/C and 46% Pt/C) demonstrated similar ORR mechanisms. We propose that Ta_0.3Ti_0.7O ₂ shows outstanding promise as a corrosion-resistant alternative to carbon as an electrocatalyst support in polymer electrolyte fuel cells.

Original language	English
Pages (from-to)	F1207-F1215
Journal	Journal of the Electrochemical Society
Volume	160
Issue number	11
DOIs	https://doi.org/10.1149/2.038311jes
State	Published - 2013

Access to Document

10.1149/2.038311jes

Cite this

@article{c4a5585290eb4fafb3ff85451a280586,

title = "Ta0.3Ti0.7O2 electrocatalyst supports exhibit exceptional electrochemical stability",

abstract = "Tantalum (Ta) modified TiO2 was synthesized using a sol-gel procedure and evaluated for use as an electrocatalyst support. Platinumnanoparticles were deposited on this support via the incipient wetness method. X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray energy dispersive spectroscopy (XEDS), X-ray photoelectron spectroscopy (XPS) and nitrogen desorption were used to investigate their microstructure. Of the formulations studied, Ta0.3Ti0.7O2 possessed an adequate powder electronic conductivity of 0.2 S/cm. The capacitance of this Ta0.3Ti0.7O2 support changed by only 12\% whereas the pseudocapacitance of a carbon benchmark changed by over 100\% over 10,000 support stability test cycles (support stability test protocol: 1.0-1.5 V vs. RHE at a scan rate of 500 mV/s in a 0.1MHClO4 electrolyte at 25?C) under identical test conditions. The stability of 20\% Pt/Ta0.3Ti 0.7O2, 20\% Pt/C, and 46\% Pt/C (commercial, TKK) catalysts were evaluated by monitoring the evolution of the electrochemical surface area (ECSA) under load cycling (load cycling protocol: 0.6-0.95 V vs. RHE with a dwell time of 3 s at either potentials in a 0.1 MHClO4 electrolyte at 25?C). The loss in ECSA in 20\% Pt/Ta0.3Ti0.7O2 was found to be 35\% compared to 44-47\% for 20\% Pt/C and 46\% Pt/C over 10,000 load cycles. 20\% Pt/Ta0.3Ti0.7O2 yielded the following performance-related metrics: the ECSA of this electrocatalyst was 41 m2/g, the mass activity and area-specific activities for the oxygen reduction reaction (ORR) determined at 0.9 V vs. RHE in a 0.1 M HClO4 electrolyte at 25?C were 62 mA/mgPt and 151 μA/cm2 Pt, respectively. Koutecky-Levich analysis carried out to evaluate ORR kinetics suggested that all 3 catalysts (20\% Pt/Ta 0.3Ti0.7O2, 20\% Pt/C and 46\% Pt/C) demonstrated similar ORR mechanisms. We propose that Ta0.3Ti0.7O 2 shows outstanding promise as a corrosion-resistant alternative to carbon as an electrocatalyst support in polymer electrolyte fuel cells.",

author = "Amod Kumar and Vijay Ramani",

year = "2013",

doi = "10.1149/2.038311jes",

language = "English",

volume = "160",

pages = "F1207--F1215",

journal = "Journal of the Electrochemical Society",

issn = "0013-4651",

number = "11",

}

TY - JOUR

T1 - Ta0.3Ti0.7O2 electrocatalyst supports exhibit exceptional electrochemical stability

AU - Kumar, Amod

AU - Ramani, Vijay

PY - 2013

Y1 - 2013

N2 - Tantalum (Ta) modified TiO2 was synthesized using a sol-gel procedure and evaluated for use as an electrocatalyst support. Platinumnanoparticles were deposited on this support via the incipient wetness method. X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray energy dispersive spectroscopy (XEDS), X-ray photoelectron spectroscopy (XPS) and nitrogen desorption were used to investigate their microstructure. Of the formulations studied, Ta0.3Ti0.7O2 possessed an adequate powder electronic conductivity of 0.2 S/cm. The capacitance of this Ta0.3Ti0.7O2 support changed by only 12% whereas the pseudocapacitance of a carbon benchmark changed by over 100% over 10,000 support stability test cycles (support stability test protocol: 1.0-1.5 V vs. RHE at a scan rate of 500 mV/s in a 0.1MHClO4 electrolyte at 25?C) under identical test conditions. The stability of 20% Pt/Ta0.3Ti 0.7O2, 20% Pt/C, and 46% Pt/C (commercial, TKK) catalysts were evaluated by monitoring the evolution of the electrochemical surface area (ECSA) under load cycling (load cycling protocol: 0.6-0.95 V vs. RHE with a dwell time of 3 s at either potentials in a 0.1 MHClO4 electrolyte at 25?C). The loss in ECSA in 20% Pt/Ta0.3Ti0.7O2 was found to be 35% compared to 44-47% for 20% Pt/C and 46% Pt/C over 10,000 load cycles. 20% Pt/Ta0.3Ti0.7O2 yielded the following performance-related metrics: the ECSA of this electrocatalyst was 41 m2/g, the mass activity and area-specific activities for the oxygen reduction reaction (ORR) determined at 0.9 V vs. RHE in a 0.1 M HClO4 electrolyte at 25?C were 62 mA/mgPt and 151 μA/cm2 Pt, respectively. Koutecky-Levich analysis carried out to evaluate ORR kinetics suggested that all 3 catalysts (20% Pt/Ta 0.3Ti0.7O2, 20% Pt/C and 46% Pt/C) demonstrated similar ORR mechanisms. We propose that Ta0.3Ti0.7O 2 shows outstanding promise as a corrosion-resistant alternative to carbon as an electrocatalyst support in polymer electrolyte fuel cells.

AB - Tantalum (Ta) modified TiO2 was synthesized using a sol-gel procedure and evaluated for use as an electrocatalyst support. Platinumnanoparticles were deposited on this support via the incipient wetness method. X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray energy dispersive spectroscopy (XEDS), X-ray photoelectron spectroscopy (XPS) and nitrogen desorption were used to investigate their microstructure. Of the formulations studied, Ta0.3Ti0.7O2 possessed an adequate powder electronic conductivity of 0.2 S/cm. The capacitance of this Ta0.3Ti0.7O2 support changed by only 12% whereas the pseudocapacitance of a carbon benchmark changed by over 100% over 10,000 support stability test cycles (support stability test protocol: 1.0-1.5 V vs. RHE at a scan rate of 500 mV/s in a 0.1MHClO4 electrolyte at 25?C) under identical test conditions. The stability of 20% Pt/Ta0.3Ti 0.7O2, 20% Pt/C, and 46% Pt/C (commercial, TKK) catalysts were evaluated by monitoring the evolution of the electrochemical surface area (ECSA) under load cycling (load cycling protocol: 0.6-0.95 V vs. RHE with a dwell time of 3 s at either potentials in a 0.1 MHClO4 electrolyte at 25?C). The loss in ECSA in 20% Pt/Ta0.3Ti0.7O2 was found to be 35% compared to 44-47% for 20% Pt/C and 46% Pt/C over 10,000 load cycles. 20% Pt/Ta0.3Ti0.7O2 yielded the following performance-related metrics: the ECSA of this electrocatalyst was 41 m2/g, the mass activity and area-specific activities for the oxygen reduction reaction (ORR) determined at 0.9 V vs. RHE in a 0.1 M HClO4 electrolyte at 25?C were 62 mA/mgPt and 151 μA/cm2 Pt, respectively. Koutecky-Levich analysis carried out to evaluate ORR kinetics suggested that all 3 catalysts (20% Pt/Ta 0.3Ti0.7O2, 20% Pt/C and 46% Pt/C) demonstrated similar ORR mechanisms. We propose that Ta0.3Ti0.7O 2 shows outstanding promise as a corrosion-resistant alternative to carbon as an electrocatalyst support in polymer electrolyte fuel cells.

UR - https://www.scopus.com/pages/publications/84891957847

U2 - 10.1149/2.038311jes

DO - 10.1149/2.038311jes

M3 - Article

AN - SCOPUS:84891957847

SN - 0013-4651

VL - 160

SP - F1207-F1215

JO - Journal of the Electrochemical Society

JF - Journal of the Electrochemical Society

IS - 11

ER -

Ta_0.3Ti_0.7O₂ electrocatalyst supports exhibit exceptional electrochemical stability

Abstract

Access to Document

Other files and links

Fingerprint

Cite this