Fabrication and characterization of La-added MgFe2O4 as catalyst support for CO oxidation
Fabrication and characterization of La-added MgFe2O4 as catalyst support for CO oxidation
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DOI：
10.1016/j.ceramint.2021.08.175
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发表时间：
2021-08
影响因子：
5.2
通讯作者：
Akane Doi;K. Obata;S. Matsushima;H. Hojo;H. Einaga
中科院分区：
文献类型：
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作者：
Akane Doi;K. Obata;S. Matsushima;H. Hojo;H. Einaga
含铁氧化物可以作为贵金属催化剂的优良载体。因此，我们研究了含铁混合氧化物负载贵金属的催化性能。用苹果酸络合法制备了MgFe2O4和La掺杂的MgFe2O4(La-MgFe2O4)，并用X射线衍射仪、氮气吸附-脱附和Fe K边X射线精细结构分析对其进行了表征。在400~800℃焙烧的镁铁氧体具有尖晶石结构，呈多孔状。La的加入增加了Fe周围的局部结构无序性，抑制了晶粒长大，影响了孔的大小，增加了比表面积。此外，还制备了负载Pd的La-γ_2O_4催化剂，发现其对CO的氧化活性高于具有代表性的Pd/Pd-Al_2O_3催化剂。进一步的程序升温还原研究表明，Pd的负载量提高了La-MgFe2O4表面晶格氧的反应活性。此外，漫反射傅里叶变换红外光谱研究表明，表面晶格氧与CO反应生成了CO2。
Fe-containing oxides can serve as excellent supports for precious metal catalysts. Therefore, we investigated the catalytic properties of noble metals supported on Fe-containing mixed oxides. MgFe2O4and La-added MgFe2O4(La-MgFe2O4) were prepared via complexation with malic acid and characterized by X-ray diffraction, N2adsorption–desorption, and Fe K-edge X-ray fine structure analysis. MgFe2O4calcined at 400–800 °C has a spinel structure and is porous. The addition of La to MgFe2O4increased the local structural disorder around Fe, suppressed grain growth, affected the pore size, and increased the specific surface area. In addition, a Pd-loaded La-MgFe2O4catalyst was prepared and found to exhibit higher activity for CO oxidation than a representative Pd/γ-Al2O3catalyst. Further, temperature-programmed reduction studies revealed that the reactivity of the surface lattice oxygen of La-MgFe2O4was enhanced by the Pd loading. Further, diffuse reflectance Fourier transform infrared spectroscopy studies showed that the surface lattice oxygen reacted with CO to form CO2.