基于二维超薄水滑石纳米片的LDO/碳基材料催化氧化甲硫醇研究

Methyl mercaptan is one of the most typical foul-smelling substances in odorous gas which possesses the speciality of excessive emission, low threshold concentration, and high toxicity. Deep removal of methyl mercaptan is necessary. Catalytic oxidation is one of the most efficient methods to eliminate methyl mercaptan, and its key issue is the choice of catalyst. Layered double oxides (LDO) derived from ultrathin layered double hydroxides (LDHs) not only inherit the advantages of high dispersion and alkaline tunability, but also has more surface defects. However, the weak stability of single layer LDO limits its wide application. The current project aims to prepare the LDO/carbon composites by sediment-sedimentation and electrostatic self-assembly methods. It can not only improve the stability of the catalyst, but also maintain its high catalytic activity. The effects of dielectric type, concentration, calcining temperature and load on the nano-particle size, distribution, basicity, and surface defects of the catalyst will be studied. The catalytic oxidation of methanol catalyzed by methanol will be evaluated. The association model between and among preparation, material properties, and catalytic oxidation performance will be established. The mechanism of catalytic oxidation of methyl mercaptan will also be studied. The research project can provide the foundation for the development of practical ultrastable LDO/carbon nanocatalysts in the catalytic oxidation of methyl mercaptan.

甲硫醇是恶臭废气中最典型的恶臭物质之一，具有来源广、嗅阈值低、毒害大等特点，在恶臭污染治理时必须进行深度脱除。催化氧化法是脱除甲硫醇的有效方法之一，其关键在于催化剂的选择。由二维超薄水滑石（LDHs）纳米材料为前驱体制备的水滑石衍生氧化物（LDO）不仅继承了传统LDO催化剂元素分散度高、碱性可调节的优点，同时具有更多的表面缺陷位，但超薄LDO材料的弱稳定性限制了其广泛应用。本项目拟通过沉积-沉淀和静电自组装手段实现超薄LDO与碳基材料的复合，既提高其稳定性，同时保持高催化活性；考察LDHs层板剥离方法、焙烧条件以及负载量等对LDO/碳基材料的粒子尺寸、分布、碱性和表面缺陷位等物化性质的影响，评价催化剂对甲硫醇的催化氧化性能，建立制备方法-材料性质-催化性能之间的关联模型，阐明甲硫醇催化氧化的反应机理。本项目研究成果可为发展实用型的超稳定LDO/碳基高效甲硫醇催化剂奠定基础。

甲硫醇是恶臭废气中最典型的恶臭物质，本项目围绕甲硫醇的催化氧化，开展了类水滑石衍生氧化物催化氧化甲硫醇研究，并基于缺陷工程策略调控水滑石衍生氧化物催化氧化甲硫醇的性能，最后开展了活性炭材料负载水滑石衍生氧化物催化氧化甲硫醇研究。利用实验与理论相结合的研究方法，对催化剂的构效关系和甲硫醇的催化氧化机理进行了深入研究。合成了二维超薄水滑石纳米片，并基于缺陷工程策略制备了富含缺陷的单原子Pt催化剂，极大的提高了催化剂的催化活性和原子经济性。研究了催化剂的反应机理，提出Pt-Cu双活性中心是促进甲硫醇催化氧化效率提升的根本原因。共计发表SCI论文7篇（包括2篇国内高水平SCI期刊），国内核心期刊论文1篇，申请发明专利2项，参加国内外学术会议4次，3名项目参与人员晋升副高级职称，培养毕业研究生3名。