Jiang Xueding, Xu Weicheng, Lai Shufeng, Chen Xin
School of Environment and Chemical Engineering, Foshan University Foshan 528000 China
RSC Adv. 2019 Feb 25;9(12):6533-6541. doi: 10.1039/c8ra10102g. eCollection 2019 Feb 22.
Considering the three-dimensional ordered network of Ni foam-supported catalysts and the toxicity effects of volatile organic compounds (VOCs), the design of proper active materials for the highly efficient elimination of VOCs is of vital importance in the environmental field. In this study, a series of Co-Mn composite oxides with different Co/Mn molar ratios grown on interconnected Ni foam are prepared as monolithic catalysts for total toluene oxidation, in which CoMnO with a molar ratio of 1 : 1 achieves the highest catalytic activity with complete toluene oxidation at 270 °C. The Co-Mn monolithic catalysts are characterized by XRD, SEM, TEM, H-TPR and XPS. It is observed that a moderate ratio of Mn/Co plays significant effects on the textural properties and catalytic activities. From the XPS and H-TPR characterization results, the obtained CoMnO (Co/Mn = 1/1) favors the excellent low-temperature reducibility, high concentration of surface Mn and Co species, and rich surface oxygen vacancies, resulting in superior oxidation performance due to the formation of a solid solution between the Co and Mn species. It is deduced that the existence of the synergistic effect between Co and Mn species results in a redox reaction: Co-Mn ↔ Co-Mn, and enhances the catalytic activity for total toluene oxidation.
考虑到泡沫镍负载型催化剂的三维有序网络结构以及挥发性有机化合物（VOCs）的毒性影响，设计合适的活性材料以高效消除VOCs在环境领域至关重要。在本研究中，制备了一系列不同Co/Mn摩尔比的Co-Mn复合氧化物，它们生长在相互连接的泡沫镍上，作为用于甲苯完全氧化的整体式催化剂，其中摩尔比为1 : 1的CoMnO在270 °C时实现了最高的催化活性，能使甲苯完全氧化。采用XRD、SEM、TEM、H-TPR和XPS对Co-Mn整体式催化剂进行了表征。结果表明，适度的Mn/Co比例对结构性质和催化活性有显著影响。从XPS和H-TPR表征结果来看，所制备的CoMnO（Co/Mn = 1/1）具有优异的低温还原性、高浓度的表面Mn和Co物种以及丰富的表面氧空位，由于Co和Mn物种之间形成了固溶体，从而具有卓越的氧化性能。据推测，Co和Mn物种之间协同效应的存在导致了氧化还原反应：Co-Mn ↔ Co-Mn，并提高了甲苯完全氧化的催化活性。
