二氧化锰纳米片可控自组装制备三维框架材料及其催化分解室内空气中甲醛的研究

Formaldehyde (HCHO) is a primary indoor air pollutant, which is harmful to human health. In order to improve indoor air quality as well as public health, it is of great significance to develop cost-effective HCHO removal materials. The applicant recently found that the microstructure of manganese dioxide (MnO2) has a significant effect on its catalytic activity. In this project, we plan to first synthesize the three-dimensional network structured MnO2-based frameworks via self-assembling MnO2 nanosheets with the assistant of freezing. We will investigate self-assembly behavior of MnO2 nanosheets under low temperature freezing，and the self-assembly rule of MnO2 nanosheets will also be explored. Furthermore, we will carry out controllable modification to its structures by adjusting the microstructure of the building unit nanosheets and controlling the self-assembly process, so as to optimize three-dimensional structures and finally enhance the catalytic performance. Moreover, the reaction kinetics will be investigated, including the effects of reaction conditions such as temperature and humidity on HCHO decomposition. The relationship between three-dimensional network structures and catalytic activity for HCHO decomposition will discussed. The catalytic reaction mechanism of HCHO molecule on catalyst surface and the key factors affecting the stability of active sites in long-term catalytic reactions will be explored in order to obtain high effective three-dimensional structured MnO2-based frameworks with long-term activity.

甲醛是室内空气中主要的气态污染物，为改善室内空气质量，保障人体健康，亟需开发经济高效的甲醛净化材料。申请人前期研究发现二氧化锰（MnO2）的微结构对其催化分解活性具有显著影响。本项目首先通过低温冷冻MnO2纳米片自组装制备具有三维网络结构的MnO2基框架材料，研究低温冷冻条件下MnO2纳米片自组装行为，探究MnO2纳米片自组装规律。在此基础之上，对MnO2基三维框架材料进行结构调控，通过调节构筑单元纳米片结构和控制自组装过程来优化三维框架结构，以达到增强其催化性能的目的。此外，还将研究甲醛分解反应动力学，考察温度、湿度等反应条件对甲醛分解性能的影响，揭示MnO2基三维框架结构与催化反应活性之间的构效关系，探明甲醛分子在催化剂表面催化分解机理以及长期反应中影响催化反应活性中心稳定的关键因素，进而制备能够长效分解室内空气中甲醛的MnO2基三维框架材料。

甲醛是室内空气中主要的气态污染物，严重影响人体健康，提高室内空气质量，解决室内甲醛污染是关系到人民身体健康的重要课题。本项目开展了锰氧化物结构调控及其自组装三维框架材料催化分解甲醛的研究工作，通过协调不同的结构调控手段，研制了能高效净化室内甲醛的催化分解材料。具体的，通过冰模板法自组装制备了高纯度三维网络结构二氧化锰框架材料，实现了甲醛在室温下的高效持续分解；进一步探究了二氧化锰自组装过程和机理，阐明了三维框架结构增强甲醛催化分解活性机制，揭示了甲醛在锰氧化物表面催化分解过程。通过位点选择性氮掺杂、暴露高活性晶面和调节锰缺陷等手段调控了组装单元锰氧化物结构，探讨了掺杂位点、暴露晶面以及氧/锰缺陷对催化分解甲醛活性的影响及其作用机制，进一步揭示了锰氧化物微结构与催化分解甲醛活性间的构效关系。通过锰氧化物的结构调控和甲醛催化分解性能研究，在锰氧化物制备、结构调控和催化分解甲醛的应用方面取得了一些列研究成果，为室内空气中甲醛的经济高效净化提供了科学和技术支撑。