甲醛室温分解分级多孔贵金属/无机纳米纤维复合催化材料的制备

Structure design and controllable fabrication of catalytic materials for highly-efficient catalytic decomposition of formaldehyde (HCHO) at room temperature is one of hotspots in material preparation field. In order to solve the existing problems of high air resistance and catalysts’ falling off from supports in actual applications for the powder-like catalytic materials, the research work will be carried out on the preparation of hierarchiclly porous noble metal/inorganic nanofiber composite catalytic materials for room-temperature decompositon of formaldehyde by combining the electrospinning technique and impregation-reduction method in this project. The effects of technique parameters, noble-metal-supported methods on the structure, morphology and performance of the prepared materials will be investigated. The effect of the composition, morphology and microstructure of catalytic materials on the catalytic performance of room-temperature decomposition of HCHO will be explored.The interaction mechanism between noble metal and supports, the mechanism of room-temperature catalytic decomposition of HCHO on supported noble metal catalysts, and the dynamics factors and related laws affecting on the reaction of room-temperature catalytic decomposition of HCHO will be investigated. The purposes of this project are to prepare highly-efficient hierarchically porous noble metal/inorganic nanofibre catalytic materials for HCHO decomposition with lower air resistance and good firmness sucessfully, to disclose the mechanism of hierarchically porous structure for enhancing catalytic activity, to deepen to understand the mechanism of room-temperature catalytic decomposition of HCHO, and to establish the dynamics model and related theory. This investigation will help to perfect the related catalytic theory and provide a new insight into the fabrication of advanced hierarchically porous indoor air purification materials.

高效甲醛室温分解催化材料的结构设计与可控制备是当前材料制备领域的前沿性热点研究之一。针对目前粉末状甲醛分解催化材料在应用中存在气阻大和容易脱落等问题，项目提出采用静电纺丝技术结合浸渍-还原方法，开展甲醛室温分解分级多孔贵金属/无机纳米纤维复合催化材料的制备研究。研究工艺参数、贵金属负载方法等对所制备材料的结构、形态和性能的影响规律；研究材料组成、形貌与微结构和室温催化分解甲醛活性的内在关系；探讨贵金属与载体之间的相互作用机制；研究贵金属催化材料室温分解甲醛的作用机理，探索影响室温催化分解甲醛反应的动力学因素与规律。目标是研制出具有低气阻、高效且结合牢固的分级多孔贵金属/无机纳米纤维甲醛室温分解催化材料；揭示分级多孔结构对催化活性的增强机制；深入理解贵金属室温催化分解甲醛的机理；建立甲醛催化分解的动力学模型及理论。本项目的研究对完善相关催化理论及发展新型分级多孔空气净化材料都具有重要意义。

甲醛是室内主要的空气污染物，甲醛去除对于提高室内空气质量和人体健康都具有非常重要的意义。针对目前粉末状甲醛分解催化材料在应用中存在气阻大和容易脱落等问题，本项目通过静电纺丝法制备柔性γ-Al2O3纤维膜，然后在其表面镀上TiO2/Co3O4涂层，再通过还原法沉积Pt(Pd)纳米颗粒于复合薄膜表面，首次成功合成柔性、重复性较好的Pt(Pd)/TiO2 (Co3O4)/γ-Al2O3复合甲醛室温氧化催化材料，其中Pt/TiO2/γ-Al2O3复合催化活性高且稳定性较好。此工作正深入开展。本项目首次采用浸涂法将TiO2表面层覆盖于棉纤维表面，再通过浸渍法和NaBH4还原法沉积Pt和Pd纳米颗粒（NPs）于表面，获得高效、稳定、轻质、低气阻甲醛氧化Pt（Pd）/ TiO2/棉纤维复合催化材料。它的空气阻力比粉末样品低得多，0.75 wt％Pt和1 wt%Pd为最优负载量。甲酸、CO和二氧化甲基（DOM）为主要HCHO氧化反应中间物种。研究结果已申请专利并获得授权。本项目还通过水热法制备了分等级多孔菜花状NiO微球，再通过沉积-沉淀和NaBH4还原法制备得到分等级大孔-介孔Pt/NiO微球复合催化材料，它比Pt/NiO纳米颗粒表现出更高HCHO氧化活性，且稳定性良好。通过水热法制备了γ-AlOOH纳米棒，通过浸渍-NaBH4还原法制备了HCHO甲醛室温氧化Pt/γ-AlOOH催化材料，其催化活性高于Pt/γ-Al2O3，0.2 wt% Pt为最佳负载量。以KAl(SO4)2和尿素为前驱体，以微波水热法制备了分等级多孔γ-Al2O3空心微球，以此为载体，制备了甲醛室温氧化分级多孔Pt/γ-Al2O3空心微球复合催化材料。通过本项目研究，获得了上述材料的制备工艺条件与结构属性的关系，材料组成、形貌与微结构和甲醛氧化活性的内在关系，贵金属与载体间的相互作用机制；提出了贵金属催化材料室温分解甲醛的作用机理，探索了影响室温催化分解甲醛反应的动力学因素。这些研究结果将促进相关催化理论及新型分级多孔空气净化材料的发展。此外，本项目还合成了其他环境净化功能材料：大孔/中孔甲烷氧化NiO/LaNiO3复合催化材料，高比表面（1154 m2/g）分等级多孔SiO2/C 空心微球，及高活性和稳定性的Ag3PO4/ Ag2S/g-C3N4复合光催化剂。