Guo Yige, Niu Xiaoxue, Yang Huaiyu, Chen Liwen, Ren Yizhen, Guo Huining, Wu Bo
College of Geology and Environment, Xian University of Science and Technology, Xian, 710054, China.
School of Environment, Renmin University of China, Beijing, 100872, China.
Heliyon. 2024 Jul 3;10(14):e33580. doi: 10.1016/j.heliyon.2024.e33580. eCollection 2024 Jul 30.
The oxidation rate of NO to NO is a critical parameter in the removal of NO within selective catalytic reduction (SCR) systems. LaCoO is a kind of potential catalyst to enhance the oxidation of NO to NO, it may offers an economic and stable alternative to noble metal catalysts, particularly at elevated temperatures. This study aimed to enhance the catalytic efficiency of LaCoO through strontium (Sr) doping. LaSrCoO (with varying x values of 0.1, 0.2, 0.3, 0.4) was synthesized using a sol-gel method. LaSrCoO exhibited superior NO oxidation catalytic activity compared to LaCoO, with the most notable enhancement observed at x = 0.3 (84 % conversion). This improvement can be attributed to the substitution of La with Sr, which induces lattice distortion and charge imbalance, thereby creating more oxygen vacancies that enhance the catalytic oxidation capability of LaSrCoO. However, it's important to note that an excessive amount of Sr can result in the formation of SrCO deposits on the surface of LaSrCoO, thereby diminishing its catalytic oxidation performance. The catalytic oxidation reaction behavior adhered most closely to the O-adsorbed E-R model, the surface defects in LaSrCoO playing a pivotal role in the catalytic reaction.
在选择性催化还原（SCR）系统中，NO氧化为NO₂的速率是去除NO的关键参数。LaCoO是一种增强NO氧化为NO₂的潜在催化剂，它可能为贵金属催化剂提供一种经济且稳定的替代方案，尤其是在高温下。本研究旨在通过锶（Sr）掺杂提高LaCoO的催化效率。采用溶胶 - 凝胶法合成了LaSrCoO（x值分别为0.1、0.2、0.3、0.4）。与LaCoO相比，LaSrCoO表现出优异的NO氧化催化活性，在x = 0.3时观察到最显著的增强（转化率为84%）。这种改进可归因于Sr对La的取代，这会引起晶格畸变和电荷不平衡，从而产生更多氧空位，增强了LaSrCoO的催化氧化能力。然而，需要注意的是，过量的Sr会导致在LaSrCoO表面形成SrCO沉积物，从而降低其催化氧化性能。催化氧化反应行为最符合O吸附的E - R模型，LaSrCoO中的表面缺陷在催化反应中起关键作用。
