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论文类型：期刊论文

发表时间：2009-07-31

发表刊物：APPLIED CATALYSIS A-GENERAL

收录刊物：SCIE、EI

卷号：364

期号：1-2

页面范围：42-47

ISSN号：0926-860X

关键字：Hematite; Amino acids; Hydrothermal method; Gold catalysts; CO oxidation

摘要：Synthesis of shape- and size- controlled alpha-Fe2O3 nanoparticles was performed through a hydrothermal method assisted with amino acids. The products were characterized by transmission electron microscopy and X-ray diffraction. It was found that the type of amino acids has significant impact on the shape and size of the obtained alpha-Fe2O3 nanoparticles. The use of acidic amino acids typically leads to the formation of alpha-Fe2O3 nanoparticles with spindle shape. However, rhombohedrally shaped alpha-Fe2O3 nanoparticles were formed in the case of basic amino acids. When gold colloidal nanoparticles were deposited on the surfaces of alpha-Fe2O3 nanoparticles, Au/alpha-Fe2O3 catalysts display substantial differences in catalytic activities in CO oxidation for the differently shaped alpha-Fe2O3 nanoparticles used as supports. In general, spindle shaped Au/alpha-Fe2O3 shows higher catalytic activity than catalysts based on rhombohedral iron oxide. Under our catalytic test conditions, for spindle shaped Au/alpha-Fe2O3 catalyst, large hematite crystals induce higher catalytic activity than smaller ones, whereas for rhombohedral Au/alpha-Fe2O3 catalysts, medium-sized alpha-Fe2O3 nanocrystals show high catalytic activity for CO oxidation. (C) 2009 Elsevier B.V. All rights reserved.