Abstract:
Herein, we propose preferential dissolution paired with Cu-doping as an effective method for synergistically modulating the A- and B-sites of LaMnO3 perovskite. Through Cu-doping into the B-sites of LaMnO3, specifically modifying the B-sites, the double perovskite La2CuMnO6 was created. Subsequently, partial La from the A-sites of La2CuMnO6 was etched using HNO3, forming novel La2CuMnO6/MnO2 (LCMO/MnO2) catalysts. The optimized catalyst, featuring an ideal Mn:Cu ratio of 4.5:1 (LCMO/MnO2-4.5), exhibited exceptional catalytic ozonation performance. It achieved approximately 90% toluene degradation with 56% selectivity toward CO2, even under ambient temperature (35 °C) and a relatively humid environment (45%). Modulation of A-sites induced the elongation of Mn-O bonds and decrease in the coordination number of Mn-O (from 6 to 4.3) in LCMO/MnO2-4.5, resulting in the creation of abundant multivalent Mn and oxygen vacancies. Doping Cu into B-sites led to the preferential chemisorption of toluene on multivalent Cu (Cu(I)/Cu(II)), consistent with theoretical predictions. Effective electronic supplementary interactions enabled the cycling of multiple oxidation states of Mn for ozone decomposition, facilitating the production of reactive oxygen species and the regeneration of oxygen vacancies. This study establishes high-performance perovskites for the synergistic regulation of O3 and toluene, contributing to cleaner and safer industrial activities.
摘要:
在这里,我们建议优先溶解与Cu掺杂配对,作为协同调节LaMnO3钙钛矿的A和B位的有效方法。通过将Cu掺杂到LaMnO3的B位,特别是修饰B位,制造了双钙钛矿La2CuMnO6。随后,使用HNO3蚀刻La2CuMnO6A位的部分La,形成新型La2CuMnO6/MnO2(LCMO/MnO2)催化剂。优化后的催化剂,具有理想的Mn:Cu比为4.5:1(LCMO/MnO2-4.5),表现出优异的催化臭氧化性能。甚至在环境温度(35°C)和相对潮湿的环境(45%)下,它实现了约90%的甲苯降解,对CO2的选择性为56%。A位的调节引起LCMO/MnO2-4.5中Mn-O键的伸长和Mn-O配位数的减少(从6减少到4.3),从而产生了丰富的多价Mn和氧空位。将Cu掺杂到B位导致甲苯在多价Cu(Cu(I)/Cu(II))上的优先化学吸附,与理论预测一致。有效的电子补充相互作用使Mn的多个氧化态循环进行臭氧分解,促进活性氧的产生和氧空位的再生。本研究建立了用于O3和甲苯协同调节的高性能钙钛矿,有助于更清洁和更安全的工业活动。