A Broadband Sum-frequency Generation Vibrational Spectrometer to Probe Adsorbed Molecules on Nanoparticles

Abstract Characterizing high-surface-area powders under near-ambient and high-pressure environments has obtained more and more attraction in the field of heterogeneous catalysis in the last decades. Here, we present an easy-operated internal heterodyne phase-resolved sum-frequency generation vibrational spectroscopy (SFG-VS) setup with the z-cut α-quartz as the internal phase reference. It is equipped with CO 2 laser to heat the substrate of α-quartz in a non-contacted way, which enables us to realize high sensitive SFG vibrational spectral measurements under high pressure and high temperature conditions. It has been demonstrated with CO adsorbed on platinum nanoparticles under the high CO pressure and the high temperature environment and sodium dodecyl sulfate film on α-quartz.