原子尺度下甲烷完全燃烧过程中Pd基催化剂的结构演变与催化性能的原位电镜研究

本项目拟以环境透射电镜和原位气氛样品杆系统为主要研究手段，在原子尺度下实时观测Pd及其合金催化剂在甲烷完全燃烧过程中的表面结构变化，并采用在线质谱仪来实时检测CH4催化反应性能，进而将催化剂的结构转变与其催化甲烷燃烧的性能直接关联起来。结合催化材料的构效关系和第一性原理理论计算，对Pd及其合金催化甲烷完全燃烧的反应机理进行了深入研究，特别是催化燃烧反应中的迟滞现象和水中毒现象。

We propose an “operando" TEM technique that combines the atomic-scale characterization of Pd-based catalysts during CH4 catalytic combustion reaction with the simultaneous measurement of the catalyst activity using on-line mass spectroscopy. The in situ gas involved transmission electron microscopy is able to study dynamic gas-solid interactions under reacting gas conditions at elevated temperature and ambient pressure (up to 1bar) with atomic resolution. By correlating catalytic data with operando TEM observations, the structure-reactivity relations in CH4 catalytic combustion will be achieved. Combining these results and first principle calculations, we can get a comprehensive understanding on the catalytic mechanism of CH4 combustion, especially the so-called hysteresis phenomenon and water poisoning on Pd-based catalysts.