用于CO氧化的Mn-Zr-Ce、Mn-Ce和Mn-Zr氧化物催化剂的热稳定性研究
The Study of Thermal Stability of Mn-Zr-Ce, Mn-Ce and Mn-Zr Oxide Catalysts for CO Oxidation.
作者信息
Afonasenko T N, Glyzdova D V, Yurpalov V L, Konovalova V P, Rogov V A, Gerasimov E Yu, Bulavchenko O A
机构信息
Center of New Chemical Technologies BIC, Boreskov Institute of Catalysis, Neftezavodskaya st., 54, Omsk 644040, Russia.
Boreskov Institute of Catalysis SB RAS, Lavrentiev Ave. 5, Novosibirsk 630090, Russia.
出版信息
Materials (Basel). 2022 Oct 27;15(21):7553. doi: 10.3390/ma15217553.
MnO-CeO, MnO-ZrO, MnO-ZrO-CeO oxides with the Mn/(Zr + Ce + Mn) molar ratio of 0.3 were synthesized by coprecipitation method followed by calcination in the temperature range of 400-800 °C and characterized by XRD, N adsorption, TPR, TEM, and EPR. The catalytic activity was tested in the CO oxidation reaction. It was found that MnO-CeO, MnO-ZrO-CeO, MnO-ZrO catalysts, calcined at 400-500 °C, 650-700 °C and 500-650 °C, respectively, show the highest catalytic activity in the reaction of CO oxidation. According to XRD and TEM results, thermal stability of catalysts is determined by the temperature of decomposition of the solid solution Mn(Ce,Zr)O. The TPR-H and EPR methods showed that the high activity in CO oxidation correlates with the content of easily reduced fine MnO particles in the samples and the presence of paramagnetic defects in the form of oxygen vacancies. The maximum activity for each series of catalysts is associated with the start of solid solution decomposition. Formation of active phase shifts to the high-temperature region with the addition of zirconium to the MnO-CeO catalyst.
采用共沉淀法合成了Mn/(Zr + Ce + Mn)摩尔比为0.3的MnO-CeO、MnO-ZrO、MnO-ZrO-CeO氧化物，随后在400-800℃温度范围内进行煅烧，并通过XRD、N吸附、TPR、TEM和EPR对其进行表征。在CO氧化反应中测试了催化活性。结果发现，分别在400-500℃、650-700℃和500-650℃煅烧的MnO-CeO、MnO-ZrO-CeO、MnO-ZrO催化剂在CO氧化反应中表现出最高的催化活性。根据XRD和TEM结果，催化剂的热稳定性由固溶体Mn(Ce,Zr)O的分解温度决定。TPR-H和EPR方法表明，CO氧化反应中的高活性与样品中易于还原的细小MnO颗粒的含量以及氧空位形式的顺磁缺陷的存在有关。每一系列催化剂的最大活性与固溶体分解的开始有关。随着向MnO-CeO催化剂中添加锆，活性相的形成向高温区域移动。
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