Li R, Yang Y, Sun N, Kuai L. Mesoporous Cu-Ce-O
x Solid Solutions from Spray Pyrolysis for Superior Low-Temperature CO Oxidation.
Chemistry 2019;
25:15586-15593. [PMID:
31574171 DOI:
10.1002/chem.201903680]
[Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Indexed: 11/10/2022]
Abstract
Development of Pt group metal-free catalysts for low-temperature CO oxidation remains critical. In this work, active and stable mesoporous Cu-Ce-Ox solid solutions are prepared by using spray pyrolysis. The specific surface areas and pore volumes reach as high as 170 m2 g-1 and 0.24 cm3 g-1 , respectively. The results of CO oxidation study suggest that (1) the catalyst obtained by spray pyrolysis possesses much higher activity than those made by co-precipitation, sol-gel, and hydrothermal methods; (2) the optimal Cu0.2 -Ce0.8 -Ox solid solution presents a reactivity over 28 times that of both single-component CuO and CeO2 at 70 °C. Based on the study of pure-phase Cu-Ce-Ox solid solutions by selective leaching of segregated CuOx species, the active center for CO oxidation is confirmed as the bimetallic Cu-Ce-O site, whereas the individual CuOx particles not only act as spectators but also block the active Cu-Ce-O sites. A low apparent activation energy of approximately 48 kJ mol-1 is detected for CO oxidation at the Cu-Ce-O site, making Cu-Ce-Ox solid solutions able to present high activity at low temperature. Furthermore, the Cu-Ce-Ox catalysts exhibit excellent stability and thermal tolerance toward CO oxidation.
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