非热等离子体气相梯度激发协同催化高效转化CO2过程机理研究

Carbon dioxide (CO2) elimination and utilization is a hot research topic in the field of environmental and energy. Plasma enhanced CO2 hydrogenation is one of the new formed technology. This project is carried out to solve the problems of the complicated processes and mechanisms about CO2 catalytic conversion in a dielectric barrier discharge (DBD)-catalytic synergy system. Based on the two stage plasma-catalytic construction, a method of gas phase non-thermal plasma excitation coupled with ZnO based catalysts for CO2 conversion with high efficiency is proposed. Various excitation conditions are introduced to study the adsorption and activation processes of different CO2 excited species. And then, the catalysts are modified by noble/transition metal and its oxidation species (Pd; Cu; ZrO2) to reveal the roles of active sites on CO2 adsorption and its selectivity hydrogenation processes. Various in situ method are used to identify the synergy effects and reaction processes with the combination of theoretical computation from the molecular/atom level. Moreover, the catalysts active sites and reaction pathways are modified according to the theory mentioned above to achieve the goal of CO2 catalytic conversion with high efficiency and stability under a relative low temperature. This research will provide the scientific basis for CO2 conversion in plasma-catalytic system.

二氧化碳（CO2）的减排与利用是环境与能源领域的热点，等离子体协同催化是CO2还原转化的新兴技术之一。非热等离子体-催化协同过程物种繁多、反应复杂，其协同机制和过程机理等关键科学问题尚不清楚。本项目采用介质阻挡放电（DBD）气相梯度激发耦合ZnO基催化剂高效转化CO2，调控CO2激发条件，解析不同激发状态下ZnO表面物种的吸附活化过程，通过贵金属/过渡金属及其氧化物（Pd; Cu; ZrO2）修饰，揭示ZnO基催化剂不同活性中心对CO2选择性催化还原性能的作用机制。构建多手段联合的原位表征技术体系并辅以理论计算，从分子/原子尺度揭示DBD气相激发协同ZnO基催化剂高效转化CO2的协同机制及过程机理，在此基础上调变催化剂活性中心和优化反应路径，实现CO2的低温、高效、稳定催化转化。本研究将为等离子体-催化协同体系中CO2的资源化提供科学依据。

二氧化碳（CO2）的减排与利用是实现“双碳”目标的重要途径。等离子协同催化是CO2还原转化的新兴技术之一。本项目采用介质阻挡放电（DBD）气相梯度激发耦合ZnO基催化剂高效转化CO2，探究了放电过程中介质填充种类、输入功率等多因素对催化反应性能（转化率、选择性）的影响规律；通过调节Pd/ZnO催化剂的Pd负载量，研究了在等离子体激发条件下CO2在催化剂表面的吸附活化特性及重要中间物种的演变规律，阐明了等离子体激发条件下CO2和H2在催化剂表面碱性位点的吸附活化过程；通过调变金属-载体相互作用及催化剂活性中心数量，探究了Pd-ZnO界面与催化活性之间的构效关系；利用在线质谱和原位红外表征手段，同步观测了反应物分子和活性中间体在催化剂表面的反应路径，揭示了催化剂协同非热等离子体选择性催化转化CO2的过程机理，在此基础上调变催化剂活性中心和优化反应参数，实现了CO2的低温、高效、稳定催化转化。本研究为等离子体-催化协同体系中CO2的资源化提供科学依据。