二维和频振动光谱研究直接甲醇燃料电池阳极电催化机理及能量转移

直接甲醇燃料电池是最有应用前景的燃料电池之一，甲醇在铂金属阳极上的氧化反应是该电池发生的重要过程。然而，较高的氧化过电位制约了该电池的工作效率。目前广为接受的甲醇氧化的双途径机理虽然可以在一定程度上解释该催化反应中的高氧化过电位，但对其机理的认识仍然不很完全，尤其是对吸附物与电极之间的相互作用和能量转移尚未报道。和频振动光谱（SFG）已经逐渐成为研究电化学界面的谱学方法。本研究首次用二维和频振动光谱（2D-SFG）研究酸性条件下在Pt、Pd电极上直接甲醇电催化反应中吸附物的物种、光谱、取向、相互作用、电催化反应机理及其超快能量转移动力学。此外也研究电极的几何因素（单晶、多晶、晶面取向）、溶液pH值、温度、电磁激励方式等因素对上述过程的影响。本研究将会极大地更新、深化和丰富对甲醇阳极电催化反应机理的深层次认识，也为理性设计催化剂提供一定的理论指导。

The direct methanol fuel cell (DMFC) is one of the most promising fuel cells. The methanol oxidation reaction (MOR) on the platinum anode are the important processes in the DMFC. However, higher oxidation overpotential restricts the work efficiency of the DMFC. Although the widely accepted dual path mechanism of the methanol oxidation can in a certain extent explain the high overoxidation potential in the catalytic reactions, the reaction mechanism remains unclear. Especially the interactions between adsorbed species and electrode and ultrafast energy transfer have not been addressed yet. Vibrational Sum Frequency Generation Spectroscopy (SFG) has become a powerful spectroscopic tool to study the electrochemical interfaces. In this project we will for the first time utilize Two-Dimensional Sum Frequency Generation (2D-SFG) to investigate the adsorbed species on Pt and Pd electrodes in the MOR under the acid conditions. The plan is to systematically investigate the chemical identification, molecular orientations, and the dynamics of the ultrafast energy transfer of the adsorbed species and understand the interactions between the adsorbents and electrodes as well as the MOR mechanisms. Subsequently we will further examine the effect of the electrode geometry (monocrystalline, polycrystalline, crystal orientation), pH, temperature, electromagnetic stimulation on the processes mentioned above. This study is anticipated to yield a deep understanding of MOR mechanism and provide certain theoretical guidance for the rational design of catalysts.