Shandong University of Science and Technology, Qingdao, Shandong, 266590, PR China.
Shandong University of Science and Technology, Qingdao, Shandong, 266590, PR China.
Chemosphere. 2022 Feb;288(Pt 3):132662. doi: 10.1016/j.chemosphere.2021.132662. Epub 2021 Oct 28.
In this work, Mn(CeZr)O was synthesized by using chelation-induced synergistic self-assembly strategy for the combustion of toluene. The physicochemical properties of the synthesized catalysts were characterized by XRD, ICP-MS, SEM, TEM, XPS and N sorption. The Mn(CeZr)O catalyst with T = 225 °C exhibited improved catalytic performance than the original MnO catalyst (T = 260 °C) and had significant low-temperature activity. The relationship between catalyst activity and structure was analyzed. By substituting Ce and Zr elements into the hollow microspheres of MnO, oxygen vacancies were produced. The main factors affecting the catalytic activity of the catalyst and the reason why it remained high catalytic activity after a long period of hydrothermal treatment were discussed. After hydrothermal aging, the original pore structure of Mn(CeZr)O catalyst collapsed and the specific surface area decreased, but the overall crystallinity of the catalyst increased and the content of oxygen species in the lattice increased. The distribution of Mn and oxygen species on the catalyst surface changed significantly after hydrothermal treatment. The appropriate ratio of Mn to Mn and the ratio of lattice oxygen to adsorbed oxygen species are beneficial to the redox reaction cycle.
在这项工作中,采用螯合诱导协同自组装策略合成了 Mn(CeZr)O,用于甲苯的燃烧。通过 XRD、ICP-MS、SEM、TEM、XPS 和 N 吸附对合成催化剂的物理化学性质进行了表征。在 T = 225°C 下,Mn(CeZr)O 催化剂表现出比原始 MnO 催化剂(T = 260°C)更好的催化性能,并且具有显著的低温活性。分析了催化剂活性与结构之间的关系。通过将 Ce 和 Zr 元素取代到 MnO 的空心微球中,产生了氧空位。讨论了影响催化剂催化活性的主要因素以及催化剂在经过长时间水热处理后仍保持高催化活性的原因。水热老化后,Mn(CeZr)O 催化剂的原始孔结构坍塌,比表面积减小,但催化剂的整体结晶度增加,晶格中氧物种的含量增加。水热处理后,催化剂表面上 Mn 和氧物种的分布发生了显著变化。Mn 和晶格氧与吸附氧物种的适当比例有利于氧化还原反应循环。