纳米尺度下冷等离子体与过渡金属碳化物基催化材料耦合作用于CO2的可控活化与转化

New catalytic materials and novel molecular activation approaches were investigated in the present study for selectively catalytic CO2 reduction to CO (RWGS). Nano-sized transition metal carbide based catalysts were synthesized to study their crystal phase, morphology, electronic structure of the ad-metals being tuned by the carbide substrates, and therefore their effects on the adsorption and subsequent reaction between CO2 and H2. The study on the carbide catalysts could be expanded to transition metal nitrides and phosphides to construct muti-interfaces between the carbide-nitride and carbide-phosphide and to study the doping effects of N and P. Deep understanding on the controllable CO2 activation and conversion over the transition metal carbide based catalysts will be obtained based on the above study. On the other hand, cold-plasma was coupled with nano-sized transition metal carbides for RWGS reaction in attempt to breakthrough the thermodynamic limitations and achieve higher CO2 conversion rates at low temperatures. The nanoscale synergy between plasma and catalysis will be studied to understand the effects of catalyst’s nanostructure on discharge as well as catalyst's surface changes being induced by the plasma, in attempt to enhance the synergistic effects and energy efficiency.

项目从新的催化材料及分子活化方式入手，探索CO2选择加氢制取CO(RWGS)的可行途径。构建纳米过渡金属碳化物基催化剂，研究碳化物的不同晶型及形貌对CO2和H2活化性质的差异，研究碳化物作为基底对被分散金属的几何形貌和电子结构的调变；构建碳化物-氮化物、碳化物-磷化物复合界面，研究N、P等杂原子的嵌入对电子能级分布的调变，进而对反应物分子吸附-活化-反应路径的调控，深化对过渡金属碳化物基催化材料活化CO2性质的科学认识。同时将冷离子体与纳米催化活化相耦合，突破RWGS反应热力学平衡限制，探索CO2分子低温可控活化转化的新途径；研究催化材料的纳米结构对耦合效果的影响，包括冷等离子体对材料表面性质的调变及材料的纳米结构对放电性质的影响，揭示等离子体与催化剂在纳米尺度下的耦合作用机制，提高协同效果和能量效率。

项目围绕碳化钼形貌控制、CO2活化机制以及等离子体和催化耦合增强作用等目标，展开了纳米棒碳化钼的可控合成及其在CO2加氢反应中的催化性能研究，揭示了冷等离子体和纳米材料之间的耦合增强机制。并将上述研究拓展到CO2-CH4重整反应，以碳化钼为催化助剂，一方面增强表面电荷积累，提高放电过程的能量利用效率，另一方面促进CO2分子的活化，降低表面积碳，显著提升催化剂的稳定性。上述研究围绕碳化钼对CO2分子的活化，聚焦提升冷等离子体催化协同作用效率，在分子活化机制和冷等离子体催化协同作用机制方面的认识获得了很大的提升；并将上述理解和认识应用到反应过程控制，在CO2-H2和CO2-CH4反应体系中构建了高效碳化钼催化剂，提升反应效率。项目很好的完成了既定目标，并对工作有所拓展和延伸。