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Iridium‐Based Cubic Nanocages with 1.1‐nm‐Thick Walls: A Highly Efficient and Durable Electrocatalyst for Water Oxidation in an Acidic Medium
Author(s) -
Zhu Jiawei,
Chen Zitao,
Xie Minghao,
Lyu Zhiheng,
Chi Miaofang,
Mavrikakis Manos,
Jin Wanqin,
Xia Younan
Publication year - 2019
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201901732
Subject(s) - nanocages , electrocatalyst , overpotential , iridium , electrochemistry , catalysis , chemistry , water splitting , chemical engineering , inorganic chemistry , materials science , electrode , photocatalysis , organic chemistry , engineering
We report a highly active and durable water oxidation electrocatalyst based on cubic nanocages with a composition of Ir 44 Pd 10 , together with well‐defined {100} facets and porous walls of roughly 1.1 nm in thickness. Such nanocages substantially outperform all the water oxidation electrocatalysts reported in literature, with an overpotential of only 226 mV for reaching 10 mA cm −2 geo at a loading of Ir as low as 12.5 μg Ir cm −2 on the electrode in acidic media. When benchmarked against a commercial Ir/C electrocatalyst at 250 mV of overpotential, such a nanocage‐based catalyst not only shows enhancements (18.1‐ and 26.2‐fold, respectively) in terms of mass (1.99 A mg −1 Ir ) and specific (3.93 mA cm −2 Ir ) activities, but also greatly enhanced durability. The enhancements can be attributed to a combination of multiple merits, including a high utilization efficiency of Ir atoms and an open structure beneficial to the electrochemical oxidation of Ir to the active form of IrO x .