疏水性氧化铈基纳米材料的制备及其在含氯有机污染物低温催化净化中的应用

Hydrophobic CeO2 nanomaterials (such as nano-flower, nanorods or nanowires array, nanosheets, and core-shell structural CeO2) are synthesized by hydrothermal/solvothermal, nano-assembly or bio-template methods and then RuO2 is loaded or doped, the catalytic combustion behaviors of the chlorinated organic compounds (COCs) is investigated. The problems to be solved about catalytic combustion of COCs over CeO2 based catalysts, such as, H2O inhibiting the catalytic activity and accelerating deactivation of catalysts, and the effect of H2O or non-chlorinated organic compounds on the selectivity of HCl and the competitive adsorption on activity sites, are studied detailedly via the control of the hydrophobic properties of CeO2, which is favor to understand the reaction mechanism and provide a basis for the practical application of CeO2 based catalysts in catalytic combustion of COCs. Additionally, the results of these studies also would provide theoretical bases and practical instruction to the design of the catalyst in other sensitive catalytic oxidation process to H2O (such as low temperature/room temperature catalytic combustion of formaldehyde and CO, the treatment of waste gas containing Tritium, the low temperature hydrogen-oxygen reaction and catalytic wet oxidation of organic wastewater).

通过水热/溶剂热、纳米自组装、生物模板等方法合成出具有疏水性质的CeO2纳米材料（如纳米花、纳米棒或线阵列、纳米片以及核壳结构的CeO2），然后负载或掺杂RuO2，研究含氯有机化合物在其上的催化燃烧行为。通过催化剂疏水性质的调变试图解决含氯烃类在CeO2基催化剂上催化燃烧所存在的诸如H2O严重抑制催化剂活性、导致催化剂失活等问题，以及探索H2O或非含氯烃类的存在对HCl选择性、活性位竞争吸附等的影响从而对反应机理进行研究，为CeO2基催化剂在氯代烃催化燃烧上的实际应用提供基础。同时，也为其他对H2O敏感的催化氧化过程（如甲醛、CO等的低温/室温催化燃烧净化、含氚废气处理、低温氢氧复合反应以及有机废水湿式催化氧化）用催化剂的设计提供理论基础和指导意义。

氧化铈基催化剂对含氯挥发性有机化合物（CVOCs）表现出高活性，是目前最具应用前景的催化材料之一，引起了广大科研人员的关注。本项目以CeO2纳米材料的合成与改性着手，首先成功合成了多种具有特定形貌的纳米CeO2（纳米棒、纳米立方体、纳米八面体、花状纳米片、单分散CeO2纳米带等），然后对其进行诸如Ru和VOx负载、Fe等过渡金属掺杂、亲疏水性调控（如硅烷试剂改性的超疏水CeO2、亲疏水性可调的CeO2@ZSM-5、本征疏水的CeO2纳米八面体/CeO2纳米带阵列）等方面的改性，详细研究了CVOCs（1，2-二氯乙烷，三氯乙烯，氯苯，二氯苯）在亲水性VOx/CeO2催化剂、耐水性Ru/CeO2催化剂、亲疏水性可控CeO2@ZSM-5催化剂上的催化燃烧，深入探讨了H2O对不同亲疏水能力的CeO2基催化剂催化活性、稳定性、副产物分布的影响和作用，系统地提出了CVOCs在CeO2基催化剂上催化燃烧的途径和机理。另外，扩展性地将CeO2@ZSM-5杂化纳米材料应用于甲烷的高温催化燃烧，其表现出高的抗烧结、耐水和耐氧能力。