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Selective Dissolution of A‐Site Cations in ABO 3 Perovskites: A New Path to High‐Performance Catalysts
Author(s) -
Si Wenzhe,
Wang Yu,
Peng Yue,
Li Junhua
Publication year - 2015
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201502632
Subject(s) - catalysis , dissolution , perovskite (structure) , oxide , alloy , inorganic chemistry , corrosion , chemistry , materials science , inert , chemical engineering , metallurgy , crystallography , organic chemistry , engineering
Selective dissolution is a common corrosion process in dealloying in which an alloy is immersed in acid to remove the active element, leaving behind an inert constituent. We introduce this technique into the treatment of oxide catalysts. A three‐dimensionally ordered macroporous LaMnO 3 perovskite has been prepared and treated with diluted HNO 3 to selectively remove La cations, acquiring a novel γ‐MnO 2 ‐like material. LaMnO 3 is not a satisfactory catalyst on CO oxidation. Upon the removal of La cations, the obtained sample showed a significantly higher CO oxidation catalytic activity ( T 50 =89 °C) than the initial precursor LaMnO 3 ( T 50 =237 °C) and ordinary γ‐MnO 2 ( T 50 =148 °C). A large surface area, a high degree of mesoporosity, excellent low‐temperature reducibility, and especially improved surface oxygen species are deduced to be responsible for CO oxidation at lower temperatures.