Zhao Feng, Li Shuangde, Wu Xiaofeng, Yue Renliang, Li Weiman, Chen Yunfa
State Key Laboratory of Multi-phase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences Beijing 100190 P. R. China
University of Chinese Academy of Sciences Beijing 100049 P. R. China.
RSC Adv. 2019 Jan 18;9(5):2343-2352. doi: 10.1039/c8ra09626k.
CuO-CeO nanocatalysts with different amounts of Mn dopping (Mn/Cu molar ratios of 0.5 : 5, 1 : 5 and 1.5 : 5) were synthesized by flame spray pyrolysis (FSP) method and tested in the catalytic oxidation of CO. The physicochemical properties of the synthesised samples were characterized systematically, including using X-ray diffraction (XRD), Raman spectroscopy, field-emission scanning electron microscopy (FESEM), Brunauer-Emmett-Teller (BET), X-ray photoelectron spectroscopy (XPS), oxygen-temperature programmed desorption (O-TPD), hydrogen-temperature programmed reduction (H-TPR) and diffuse reflectance infrared Fourier transform spectroscopy ( DRIFTS). The results showed that the 1Mn-Cu-Ce sample (Mn/Cu molar ratio of 1 : 5) exhibited superior catalytic activity for CO oxidation, with the temperature of 90% CO oxidation at 131 °C at a high space velocity (SV = 60 000 mL g h), which was 56 °C lower than that of the Cu-Ce sample. In addition, the 1Mn-Cu-Ce sample displays excellent stability with prolonged time on CO stream and the resistance to water vapor. The significantly enhanced activity was correlated with strong synergetic effect, leading to fine textual properties, abundant chemically adsorbed oxygen and high lattice oxygen mobility, which further induced more Cu species and less formation of carbon intermediates during the CO oxidation process detected by DRIFTS analysis. This work will provide in-depth understanding of the synergetic effect on CO oxidation performances over Mn doped CuO-CeO composite catalysts through FSP method.
采用火焰喷雾热解（FSP）法合成了具有不同锰掺杂量（锰/铜摩尔比为0.5:5、1:5和1.5:5）的CuO-CeO纳米催化剂，并对其进行了CO催化氧化测试。系统地表征了合成样品的物理化学性质，包括使用X射线衍射（XRD）、拉曼光谱、场发射扫描电子显微镜（FESEM）、布鲁诺尔-埃米特-泰勒（BET）、X射线光电子能谱（XPS）、氧程序升温脱附（O-TPD）、氢程序升温还原（H-TPR）和漫反射红外傅里叶变换光谱（DRIFTS）。结果表明，1Mn-Cu-Ce样品（锰/铜摩尔比为1:5）在CO氧化反应中表现出优异的催化活性，在高空速（SV = 60000 mL g h）下，90% CO氧化的温度为131℃，比Cu-Ce样品低56℃。此外，1Mn-Cu-Ce样品在长时间的CO气流中表现出优异的稳定性以及对水蒸气的抗性。活性的显著增强与强烈的协同效应相关，从而导致良好的织构性质、丰富的化学吸附氧和高的晶格氧迁移率，这进一步促使在DRIFTS分析检测到的CO氧化过程中形成更多的铜物种和更少的碳中间体。这项工作将深入理解通过FSP法制备的锰掺杂CuO-CeO复合催化剂上协同效应对CO氧化性能的影响。
