Highly Stable and Active Pt-Cu Oxygen Reduction Electrocatalysts Based on Mesoporous Graphitic Carbon Supports

被引：101

作者：

Gupta, Gaurav ^{[1
]}

Slanac, Daniel A. ^{[1
]}

Kumar, Pavan ^{[1
]}

Wiggins-Camacho, Jaclyn D. ^{[1
]}

Wang, Xiqing ^{[2
]}

Swinnea, Steven ^{[1
]}

More, Karren L. ^{[2
]}

Dai, Sheng ^{[2
]}

Stevenson, Keith J. ^{[1
]}

Johnston, Keith P. ^{[1
]}

机构：

[1] Univ Texas Austin, Austin, TX 78712 USA

[2] Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA

来源：

CHEMISTRY OF MATERIALS | 2009年 / 21卷 / 19期

基金：

美国国家科学基金会;

关键词：

SHELL NANOPARTICLE ELECTROCATALYSTS; CO-AU ELECTROCATALYSTS; PARTICLE-SIZE; FUEL-CELLS; BIMETALLIC NANOPARTICLES; DURABILITY ENHANCEMENT; CATALYTIC CATHODE; ALLOY CATALYSTS; PLATINUM; SILICA;

D O I：

10.1021/cm901203n

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The activity of oxygen reduction catalysts for fuel cells often decreases markedly (30-70%) during potential cycling tests designed to accelerate catalyst degradation. Herein we achieved essentially no loss in electrochemical surface area and catalyst activity during potential cycling from 0.5 to 1.2 V for presynthesized Pt-Cu nanoparticles of controlled composition that were infused into highly graphitic disordered mesoporous carbons (DMC). The high stability is favored by the strong metal-support interactions and low tendency for carbon oxidation, which mitigates the mechanisms of degradation. Electrochemical dealloying transforms the composition from Pt20Cu80 to Pt85Cu15 with a strained Pt-rich shell, which exhibits an enhanced ORR activity of 0.46 A/mg(Pt), > 4 fold that of pure Pt catalysts. The high uniformity in particle size and composition both before and after dealloying, as a consequence of the presynthesis/infusion technique, is beneficial For elucidating the mechanism of catalyst activity and, ultimately, for designing more active catalysts.

引用

页码：4515 / 4526

页数：12

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