Dynamic Metal-Polymer Interaction for the Design of Chemoselective and Long-Lived Hydrogenation Catalysts

S. Lee, S.-J. Shin, H. Baek, Y. Choi, K, Hyun, M. Seo, K. Kim, D.-Y. Koh, H.-J. Kim*, M. Choi*, Sci. Adv., 6, 1-10 (2020)

https://doi.org/10.1126/sciadv.abb7369

Metal catalysts are generally supported on hard inorganic materials because of their high thermochemical stabilities. Here, we support Pd catalysts on a thermochemically stable but “soft” engineering plastic, polyphenylene sulfide (PPS), for acetylene partial hydrogenation. Near the glass transition temperature (~353 K), the mobile PPS chains cover the entire surface of Pd particles via strong metal-polymer interactions. The Pd-PPS interface enables H2 activation only in the presence of acetylene that has a strong binding affinity to Pd and thus can disturb the Pd-PPS interface. Once acetylene is hydrogenated to weakly binding ethylene, re-adsorption of PPS on the Pd surface repels ethylene before it is further hydrogenated to ethane. The Pd-PPS interaction enables selective partial hydrogenation of acetylene to ethylene even in an ethylene-rich stream and suppresses catalyst deactivation due to coke formation. The results manifest the unique possibility of harnessing dynamic metal-polymer interaction for designing chemoselective and long-lived catalysts.