铈基催化剂在甲苯氧化中涉氧参量演变的电子转移研究

Volatile organic compounds (VOCs) is one of the most important airborne pollutants. Ceria-based catalysts are widely applied in VOCs catalytic oxidation due to their superior performance. The nature of VOCs oxidation over catalyst includes the evolution of oxygen vacancies (OV), the mobility of oxygen species (OS) and charge transport (CT). Aiming at the insufficient of quantitative research on OV, OS and CT, this study systematically deals with the quantitative research on CT of oxygen-related parameters in VOCs oxidation, since the migration and transformation mechanism of OV and OS were identified in previous works. Specifically, to control elaborately the morphology and size of ceria-based catalysts by optimizing the synthesis parameters of hydrothermal and template methods, thus regulating the strength/concentration of OV and OS. Using various in situ methods of Raman, XPS and IR, combining theoretical calculation, the evolution and migration of OV and OS during toluene oxidation are studied, as well as the migration mechanism of oxygen-related parameters. The CT procedure is investigated with real-time characterization methods, to elucidate CT mechanism of oxygen-related parameters evolution. This work is supposed to provide scientific guidance for controlling oxygen-related parameters and CT, thus offering basic data for promoting the performance of ceria-based catalysts.

挥发性有机物（VOCs）是重要的大气污染物。铈基催化剂因其优异的性能广泛应用于VOCs催化氧化，而VOCs的氧化本质上是其在催化剂上发生的氧空位的演变和氧物种的迁移、电子转移过程。项目针对目前氧空位和氧物种定量研究及电子迁移过程甄别的空缺，基于前期所研究的氧空位和氧物种迁移转化机制，系统地定量研究反应过程中涉氧参量演变的电子转移。通过水热及模板合成法优选铈基催化剂关键制备条件，精细控制其形貌尺寸，对氧空位和氧物种强度/浓度进行有限调控。利用原位的拉曼、XPS、红外等实时表征手段结合理论计算，研究铈基催化剂上甲苯氧化过程中氧空位演变规律和活性氧物种迁移过程，探索反应中涉氧参量的演变机制；实时研究涉氧参量演变的电子转移过程，阐明其作用机制。研究成果对调控铈基催化剂上涉氧参量和电子转移具有科学指导意义，为提升铈基催化剂性能积累基础数据。

挥发性有机物（VOCs）防治已成为我国污染控制重点之一，为此，国家出台了一系列政策进行治理。然而我国VOCs控制工作依然为大气环境治理的短板，因此，VOCs的控制已成为我国大气环境治理的焦点问题。对此，研制低温下活性高、抗失活能力强的铈基催化剂，定量研究反应过程中涉氧参量演变的电子转移具有重要科学意义和应用前景。本项目基于水热及模板合成法优选铈基催化剂关键制备条件，精细控制其形貌尺寸，对氧空位和氧物种强度/浓度进行有限调控。利用原位的拉曼、XPS、红外等实时表征手段结合理论计算，明确铈基催化剂上甲苯氧化过程中氧空位演变规律和活性氧物种迁移过程，探明反应中涉氧参量的演变机制；实时研究涉氧参量演变的电子转移过程，阐明其作用机制。研究成果对调控铈基催化剂上涉氧参量和电子转移具有科学指导意义，为提升铈基催化剂性能积累基础数据。