Zeng Yiqing, Wang Yanan, Zhang Shule, Zhong Qin
School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, PR China.
School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, PR China.
J Colloid Interface Sci. 2020 Nov 15;580:49-55. doi: 10.1016/j.jcis.2020.07.023. Epub 2020 Jul 9.
Lanthanum manganite (LaMnO) with magnesium (Mg) substituted the A- and B-sites were reported for the first time in this work. The Mg substituted LaMnO catalysts were prepared by means of citric acid sol-gel method. The impact of partial substitution of Mg and its substitution site on the catalytic performance of LaMnO in nitric oxide (NO) oxidation was investigated. Through series of characterizations, it was found that Mg substitution at both A- and B-sites improves the specific surface area, Mn content, reactivity of surface oxygen species, redox property and NO adsorption capacity of LaMnO. However, Mg substitution at the A-site of LaMnO can cause the total charge imbalance of B-site, which significantly improves the amount and reactivity of surface active oxygen species. Therefore, the catalytic activity of the samples decreases in the order: LaMgMnO > LaMnMgO > LaMnO. This study will shed more light on the fundamental understanding and designing of perovskite catalyst.
在本工作中首次报道了用镁（Mg）取代A位和B位的镧锰氧化物（LaMnO）。采用柠檬酸溶胶-凝胶法制备了Mg取代的LaMnO催化剂。研究了Mg的部分取代及其取代位点对LaMnO催化一氧化氮（NO）氧化性能的影响。通过一系列表征发现，A位和B位的Mg取代均提高了LaMnO的比表面积、Mn含量、表面氧物种的反应活性、氧化还原性能和NO吸附容量。然而，LaMnO的A位Mg取代会导致B位的总电荷失衡，从而显著提高表面活性氧物种的数量和反应活性。因此，样品的催化活性顺序为：LaMgMnO > LaMnMgO > LaMnO。本研究将为钙钛矿催化剂的基础理解和设计提供更多启示。
