室温分解甲醛超低载量原子级Pt/碳基复合催化材料构建

Catalytic decomposition technology at ambient condition can be considered as one of the most effective and economical alternatives for the removal of formaldehyde. The rational design and controllable preparation of catalytic materials with superior performance is the key for the applications of catalytic decomposition of formaldehyde at ambient condition. In the project, by introducing the appropriate heteratoms to carbon nanostructures, the Pt or Au particles will be highly dispersed on carbon-based nanostructures in the atom-scale with a tuned electronic state and an enhanced catalytic performance. This can be owned to the achoring and coordination effects of the heteratoms to Pt or Au as well as the adjusted electronic state of carbon-based nanostructures by these doped heteratoms. The preparation technique will be improved for the cotrollable synthesis of the graphene and carbon nanocages doped with nitrogen, sulfur and phosphorous atoms. The effect of the doping components, chemical composites and comtents on the chemical and physical properties especially the electronic states of graphene and carbon nanocages will be thoroughly investigated. The Pt or Au nanoparticles will be supported on these carbon-based nanostructures in atom-scale with ultrasonic-assisted impregnation methods, solvothermal and microwave-assisted polyol reduction methods.The effects of the supports on the metal particle diserpsion, crystal degree, electronic state, redox, hydroxyl oxygen contents will be probed, and the relation of the tuned electronic state to the catalytic performance will be collected for constructing the advanced catalytic materials. We will study the kinetics of the catalytic decomposition and mechanism of formaldehyde on the prepared catalytic materials at ambient condition, which will supply the rules for designing advanced Pt-based catalytic materials and exploring non-Pt ones for the abatement of formaldehyde.

室温催化分解技术是净化室内甲醛最有效的途径之一。高效催化材料的理性设计与可控制备是室温催化分解甲醛技术走向应用的关键。本项目提出在碳基材料中引入具有孤对电子的杂原子，利用杂原子的孤对电子与Pt、Au金属的空轨道配位，实现Pt、Au粒子超低载量原子级固载和电子态调控，构建高效室温分解甲醛催化材料。本研究将发展杂原子掺杂碳纳米结构的合成技术，可控制备氮、硫、磷掺杂石墨烯、碳纳米笼。通过浸渍、溶剂热、微波辅助乙二醇还原法，利用碳载体中杂原子的锚定与配位作用，在载体表面实现超低载量Pt、Au粒子的原子级固载，揭示载体中杂原子掺杂类型、化学态和含量对催化活性组分的粒径、分散性、晶化程度、氧化还原性及催化材料表面电子态的调变规律，确定催化材料表面电子态与室温催化分解甲醛性能之间的定性、定量关系，揭示催化机理，以此引导高效Pt系催化材料的设计，实现非Pt催化材料的有效开发。

室内空气质量与人体健康息息相关，甲醛是室内环境中危害最严重的VOCs 气体，迫切需要研发高效、安全、稳定且无二次污染的室内甲醛净化技术和材料。本项目基于传统室温催化氧化技术与光催化技术特点，利用杂原子掺杂对催化剂表面电子态调控，开展了系列深入、系统的甲醛催化氧化去除研究。一方面，在催化剂中掺杂引入碱金属构建了系列富电子催化剂，根据分子极化理论，碱金属的引入增强了催化剂的碱性，显著提高了催化剂对甲醛分子的吸附、活化和氧化能力；另一方面，通过杂原子掺杂调控催化剂的形貌和电子态，包括带隙、氧化还原电位、光吸收范围和强度、光生电子定向传输性能等，提高了甲醛氧化所需的活性氧物种中间体的产率，改善了甲醛光催化氧化分解的效率。本项目通过电子顺磁共振、时间分辨荧光光谱、表面光电压、在线漫反射傅立叶变换红外光谱以及DFT理论计算等技术和方法揭示了各策略对催化剂电子结构的调控和催化性能增强机制，确立了掺杂引起的催化剂表面电子态与甲醛氧化分解性能之间的定性、定量关系，为高效率、低成本、长寿命的室温甲醛净化催化剂的设计与开发提供实验依据。