Novel phenomenon of enhancement of IR absorption of CO adsorbed on nanoparticles of Pd confined in supercages of Y-zeolite

Nanoparticles of palladium were synthesized by a `ship-in-a-bottleʹ technique in supercages of Y-zeolite. The ions of Pd2+ were introduced into the zeolite by ion-exchange between PdCl2 and NaY zeolite. They were then reduced by an electrochemical method and assembled to form nanoparticals by admission and release of CO. The electrode of palladium-loading zeolite film was characterized by cyclic voltammetry, and the adsorption of carbon monoxide on the electrode was studied using in situ electrochemical FTIR reflection spectroscopy. A novel phenomenon of enhanced IR absorption (EIRA) was observed for the first time. In comparison with CO adsorbed on a massive Pd electrode, the IR absorption of CO adsorbed on nanoparticles of Pd confined in supercages of Y-zeolite has been enhanced to about 51 times.