林业工程学报2025，Vol.10Issue(3)：68-76,9.DOI:10.13360/j.issn.2096-1359.202406038
形貌调控对La/MnO2低质量浓度甲苯催化氧化性能的影响
Effect of morphological control of La/MnO2 on catalytic oxidation of low-concentration toluene
摘要
Abstract
Furniture and wooden materials are known to emit volatile organic compounds(VOCs),such as toluene,which pose significant health risks.This study investigated a highly efficient approach to the catalytic oxidation of low-concentration toluene,offering a practical and impactful solution for improving indoor air quality.Despite the increasing attention to toluene emissions,research on the catalytic oxidation of low-concentration toluene remains limited.To address this gap,the catalytic performance of La/MnO2 catalysts synthesized via hydrothermal methods was evaluated.La/MnO2 catalysts with various morphologies(particles,flowers,rods,and sheets)were successfully synthesized.The X-ray diffraction(XRD)analysis revealed that both the precursor materials and hydrothermal synthesis temperature significantly influenced catalyst crystallinity.Among the four morphologies,La/MnO2 nanosheets(NS)exhibited the lowest crystallinity,which likely resulted in more surface defects,thus enhancing catalytic activity.La/MnO2 nanosheets exhibited a highly porous surface with a combination of high specific surface area,mesopores,and a small fraction of micropores,facilitating the effective adsorption of low-concentration toluene.Additionally,the NS catalyst showed a significantly higher Mn3+/Mn4+ratio compared to the other morphologies,which facilitates the formation of oxygen vacancies.The ratio of lattice oxygen to adsorbed oxygen was nearly identical for the NS,and the lower desorption temperature of lattice oxygen further promoted the conversion of toluene to benzoate.The catalytic activity for low-concentration toluene oxidation followed this order:La/MnO2 nanosheets＞La/MnO2 nanoparticles＞La/MnO2 nanowires＞La/MnO2 nanoflowers.Notably,the La-doped NS catalyst exhibited a higher proportion of Mn3+and better catalytic performance than the undoped catalysts.At 40℃,the NS catalyst achieved a 40%toluene removal rate,demonstrating excellent durability and reusability.The NS catalyst maintained strong catalytic performance during both the initial and long-term stages,providing a reliable foundation for practical applications.Further testing revealed that,at 200℃,the La/MnO2 nanosheets achieved up to 90%toluene removal and maintained stable catalytic activity for up to 11 h.The temperature-programmed desorption(TPD)and X-ray photoelectron spectroscopy(XPS)analysis showed that the combination of La doping and the sheet-like structure promoted the formation of oxygen vacancies and low-valence manganese,which played a crucial role in enhancing the oxidation process and facilitating the transformation of oxygen species.In conclusion,the La/MnO2 nanosheets,especially with La doping,exhibited excellent catalytic performance,stability,and reusability,highlighting their strong potential for removing indoor VOCs such as toluene.With their promising catalytic activity and durability,further research into their scalability for large-scale air purification applications is highly encouraged.关键词
甲苯/La/MnO2/催化剂形貌/催化氧化Key words
toluene/La/MnO2/catalyst morphology/catalytic oxidation分类
轻工纺织引用本文复制引用
齐飞,沈隽,王伟东,陈宇,郑德宗,栗琳..形貌调控对La/MnO2低质量浓度甲苯催化氧化性能的影响[J].林业工程学报,2025,10(3):68-76,9.基金项目
国家自然科学基金(31971582). （31971582）
