氧化锌负载钯/铜光热协同催化CO2加氢制甲醇反应研究

Catalytic hydrogenation of CO2 to methanol is one of the most important routes to face the energy and environmental crises in post fossil fuel era. Traditional CO2 hydrogenation reaction suffers from the difficulty in CO2 activation at low temperatures and the limitation of thermodynamic equilibrium, leading to low methanol yield. Photothermal catalysis, a new type of catalysis involved with external field, can make up for the deficiency of the sole thermal catalysis, but the knowledge is still far from clear. In this project, we intend to introduce external light irradiation to traditional CO2 hydrogenation system over ZnO supported Pd and Cu based model catalysts by adopting a modified flow reactor equipped with a light source. We will first investigate the influence of light irradiation on the catalytic activities, and further understand the synergetic mechanism of the photo-thermal catalysis. Next, we will adopt the strategies of the doping of ZnO by light-sensitive semiconductors such as CdSe and TiO2 and the alloying of Pd and Cu by d-band metals with the surface plasmon resonance (SPR) character, to optimize the photothermal catalytic performance. At last, we will study the surface chemistry of the model catalysts, electronic properties and their effect on the adsorption of reactants and intermediates under photo-thermal reaction condition, and further unveil the relationship between catalyst structure and activity. This project would open up a novel and potential catalysis system for CO2 hydrogenation to methanol with combined thermal and photo-catalysis, and provide the knowledge about the relationship between catalyst structure and activities and about the catalyst design for methanol synthesis under mild condition.

CO2加氢制甲醇是后油气时代解决能源与环境双重问题的重要途径之一。传统热催化面临着低温CO2难以活化这一难题，且受到热力学平衡制约而导致甲醇收率偏低。光热协同催化这一新型外场耦合方式则有望弥补热催化的不足，但目前认识仍十分有限。本项目拟采用新型固定床微型光热反应装置，以Pd-ZnO和Cu-ZnO为模型催化剂考察其光热协同催化CO2加氢反应性能；研究光热复合场中活性金属表面的电子特性与反应活性和甲醇选择性之间的关系，揭示光照对热催化反应的协同机制；采取对ZnO掺杂改性和对Pd、Cu活性组分合金化策略，最大化光热协同效应；探究光热复合场下催化剂表面结构对反应物分子的吸附行为与化学反应，最终揭示构效关系。本项目的顺利实施，有望耦合热催化与光催化的优势，发展新型光热协同催化技术，丰富对光热协同作用下催化剂构效关系的认识，为温和条件下CO2加氢制甲醇高效催化剂的开发提供基础数据。

开发将CO2转化为高价值燃料或其它化工原料的绿色催化技术，是实现“双碳”目标、能源与化学工业可持续发展的重要策略之一。通过光热催化加氢技术将CO2转化为高附加值的燃料和化工原料，尤其是含氧化合物愈来愈引起大家的研究兴趣。本项目研究内容采用固定床微型光热反应装置，以PdZn合金或MOFs限域金属Cu为模型催化剂考察了其光热协同催化CO2加氢反应性能，揭示光热协同效应对甲醇活性的促进作用和相应的催化活性位点。此外，本项目还进行Zr基、Pd基以及CuZn基用于甲醇合成反应，并开发CuFe基和多组分串联催化体系用于低碳醇合成，接下来可为光热协同催化甲醇和低碳醇的制备和研究提供一些研究思路。