Yang Jingxia, Yigit Nevzat, Möller Jury, Rupprechter Günther
Institute of Materials Chemistry, Technische Universität Wien, Getreidemarkt 9/BC/01, 1060-, Vienna, Austria.
College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, Longteng Rd 333, Songjiang, Shanghai, (P.R., China.
Chemistry. 2021 Dec 6;27(68):16947-16955. doi: 10.1002/chem.202100927. Epub 2021 Jun 10.
In an effort to combine the favorable catalytic properties of Co O and CeO , nanocomposites with different phase distribution and Co O loading were prepared and employed for CO oxidation. Synthesizing Co O -modified CeO via three different sol-gel based routes, each with 10.4 wt % Co O loading, yielded three different nanocomposite morphologies: CeO -supported Co O layers, intermixed oxides, and homogeneously dispersed Co. The reactivity of the resulting surface oxygen species towards CO were examined by temperature programmed reduction (CO-TPR) and flow reactor kinetic tests. The first morphology exhibited the best performance due to its active Co O surface layer, reducing the light-off temperature of CeO by about 200 °C. In contrast, intermixed oxides and Co-doped CeO suffered from lower dispersion and organic residues, respectively. The performance of Co O -CeO nanocomposites was optimized by varying the Co O loading, characterized by X-ray diffraction (XRD) and N sorption (BET). The 16-65 wt % Co O -CeO catalysts approached the conversion of 1 wt % Pt/CeO , rendering them interesting candidates for low-temperature CO oxidation.
为了结合CoO和CeO₂的良好催化性能，制备了具有不同相分布和CoO负载量的纳米复合材料，并将其用于CO氧化。通过三种不同的基于溶胶-凝胶的路线合成了CoO修饰的CeO₂，每种路线的CoO负载量均为10.4 wt %，得到了三种不同的纳米复合形态：CeO₂负载的CoO层、混合氧化物和均匀分散的Co。通过程序升温还原（CO-TPR）和流动反应器动力学测试研究了所得表面氧物种对CO的反应活性。第一种形态表现出最佳性能，这归因于其活性CoO表面层，使CeO₂的起燃温度降低了约200°C。相比之下，混合氧化物和Co掺杂CeO₂分别存在较低分散性和有机残留物的问题。通过改变CoO负载量优化了CoO-CeO₂纳米复合材料的性能，并通过X射线衍射（XRD）和N₂吸附（BET）进行了表征。16-65 wt %的CoO-CeO₂催化剂接近1 wt % Pt/CeO₂的转化率，使其成为低温CO氧化的有趣候选材料。
