In-situ SHINERS Study of the Size and Composition Effect of Pt-based Nanocatalysts in Catalytic Hydrogenation

摘要

Understanding the structure-activity relationship of catalytic reactions at a molecular level still remains a great challenge. Herein, shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) is employed to in-situ study the catalytic hydrogenation of para-nitrothiophenol (pNTP) on Pt-based nanocatalysts with different size and composition. The nanocatalysts are assembled on pinhole-free shell-isolate nanoparticles (SHINs), which work as Raman amplifiers to enhance the Raman signals of species on the catalysts, allowing the in-situ monitoring of catalytic reactions carried out on the catalysts. Using this strategy, we find that the catalytic activity of the Pt nanocatalysts shows a volcanic trend with the Pt size, and that PtM (M=Ni or Cu) bimetallic nanocatalysts display much higher performance compared with Pt due to better activation of the nitro group. This work demonstrates that SHINERS is a promising technique for in-situ study of nanocatalysis thus can deepen the understanding of the behaviors of different catalysts.