College of Chemistry Biology and Environment, Yuxi Normal University, Yuxi, 653100, China.
Institute of Biology and Environmental Engineering, Yuxi Normal University, Yuxi, 653100, China.
Sci Rep. 2023 Feb 28;13(1):3386. doi: 10.1038/s41598-023-30465-7.
Cerium manganese bimetallic catalysts have become the focus of current research because of their excellent catalytic performance for soot combustion. Two series of cerium manganese catalysts (Na-free catalysts and Na-containing catalysts) were prepared by coprecipitation method and characterized using XRD, N adsorption-desorption, SEM, Raman, XPS, H-TPR, O-TPD, Soot-TPR-MS and in situ IR. The effects of abundant oxygen vacancies and surface highly dispersed MnO on soot catalytic combustion of cerium manganese catalysts prepared by different precipitants were analyzed. The activity test results show that the active oxygen species released by a large number of oxygen vacancies in the cerium manganese catalyst are more favorable to the soot catalytic combustion than MnO which is highly dispersed on the surface of the catalyst and has good redox performance at low temperature. Because the catalytic effect of MnO on the surface of Na-free catalysts is more dependent on the contact condition between the catalyst and the soot, this phenomenon can be observed more easily under the loose contact condition than under the tight contact condition. The activity cycle test results show that these two series of catalysts show good stability and repeated use will hardly cause any deactivation of the catalysts.
铈锰双金属催化剂因其对炭黑燃烧的优异催化性能而成为当前研究的焦点。采用共沉淀法制备了两种系列的铈锰催化剂（无钠催化剂和含钠催化剂），并通过 XRD、N 吸附-解吸、SEM、Raman、XPS、H-TPR、O-TPD、炭黑-TPR-MS 和原位 IR 进行了表征。分析了不同沉淀剂制备的铈锰催化剂中丰富的氧空位和表面高度分散的 MnO 对炭黑催化燃烧的影响。活性测试结果表明，铈锰催化剂中大量氧空位释放的活性氧物种比表面高度分散且低温下具有良好氧化还原性能的 MnO 更有利于炭黑的催化燃烧。由于无钠催化剂表面 MnO 的催化作用更依赖于催化剂与炭黑的接触条件，因此在松散接触条件下比在紧密接触条件下更容易观察到这种现象。活性循环测试结果表明，这两种系列的催化剂均表现出良好的稳定性，重复使用几乎不会导致催化剂失活。
