For nanoparticles used in the catalytic production of chemicals and fuels in liquid, the chemistries of their surface or near-surface regions in liquid are crucial for gaining a fundamental understanding of their catalytic performances. Photoelectron spectroscopy is a surface-sensitive technique; however, it is challenging to study the surfaces of catalyst nanoparticles in liquid due to the short inelastic mean free path of photoelectrons travelling in liquid and substantial vaporization of liquid at elevated temperatures or in the high-vacuum environment of a photoelectron spectrometer. I will present the method that resolves these impediments by employing graphene layers as an electron-transparent membrane to separate liquid-containing solvent, catalyst nanoparticles, and reactant from the high-vacuum environment of the photoelectron spectrometer. The surfaces of Ag nanoparticles dispersed in liquid sealed in such a graphene membrane liquid cell were characterized using photoelectron spectroscopy. This method also enables the study of the surfaces of catalyst nanoparticles in liquid reactants during catalysis at elevated temperatures.

Study surface of catalyst nanoparticles using synchrotron X-ray photoelectron spectroscopy

256th National Meeting (2018)

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