(6u) Controlled Synthesis and in-Situ Spectroscopic Study of Highly Efficient Ptfe Bimetallic and Ptrufe Trimetallic Nanocatalysts

Authors: 
Zhang, H., Xiamen University
Zhang, N., Xiamen University
Research Interests: Heterogeneous catalysis

Teaching Interests: Heterogeneous catalysis

Controlled synthesis of highly efficient nanocatalysts and studying their structure-activity relationship are of significant importance in both fundamental research and industrial applications. In this study, we developed several well defined Pt-based nanocatalysts with quasi-core-shell structure or nanoalloy structure for the preferential oxidation of CO in the presence of H2 (PROX), which is a key reaction for the production of clean H2. By means of various ex- or in-situ characterization method, such as HR-TEM, quasi-in-situ XPS and in-situ DRIFTS, the structure-activity relationships of these catalysts have been extensively studied. It was concluded that ferrous iron species could work as oxygen activation sites, and Ru could lower the CO adsorption strength. Furthermore, the utilization of Pt was much higher on nanoalloy catalysts as compared with quasi-core-shell catalysts. Based on these findings, highly efficient PtFe and PtRuFe nanoalloy catalysts with ultra-low Pt loading were designed, on which CO can be completely removed even under -50 ºC. We have also developed a novel strategy to in-situ monitoring the adsorbed species on the nanocatalysts by shell-isolated nanoparticles-enhanced Raman spectroscopy (SHINERS), which was then proved to be a general strategy for the in-situ study of heterogeneous nanocatalytic process. By this method, the interactions between CO/O2 and metal can be studied, and for the first time, direct spectroscopic evidence for the activation of O2 on ferrous center has been observed.