It is known that catalytic activity depends on the size, shape, and composition of nanoparticles. We have systematically expanded this study by synthesizing multi-functional nanoparticles of different sizes, including core–shell, yolk–shell, and hybrid nanocatalysts. We collaborated with another research group that has the capability to synthesize and fabricate novel nanocatalysts. These nanoparticles were then characterized using various surface-sensitive techniques.

We carried out catalytic reactions on nanoparticle arrays and studied the change of turnover rate and activation energy as a function of the size and composition of the nanoparticle arrays. [S. H. Joo, J. Y. Park*, J. R. Renzas, D. R. Butcher, W. Y. Huang, and G. A. Somorjai*. Size Effect of Ruthenium Nanoparticles in Catalytic Carbon Monoxide Oxidation. Nano Letters. 10, 2709 (2010).]

We showed that hot electron or surface plasmon can influence the catalytic reactions using metal-semiconductor nanostructures or metal-insulator-metal structures. By using metal–semiconductor hybrid nanocatalysts, we found that catalytic activity can be controlled by manipulation of hot electron flows generated by photon irradiation. [Sun Mi Kim, Seon Joo Lee, Seung Hyun Kim, Sangku Kwon, Ki Ju Yee, Hyunjoon Song, Gabor A. Somorjai*, and Jeong Young Park*. Hot Carrier-driven Catalytic Reactions on Pt-CdSe-Pt Nanodumbbells and Pt/GaN under Light Irradiation. Nano Letters. 13, 1352-1358 (2013).] My research efforts on this subject were highlighted in a recent review paper. [Jeong Young Park*, Sun Mi Kim, Hyosun Lee, and Ievgen Nedrygailov, Hot Electron-mediated Surface Chemistry; Toward Electronic Control of Catalytic Activity, Accounts of Chemical Research 48, 2475-2483 (2015)]

Figure. Hot electron-driven chemical reactions on Pt-CdSe-Pt nanostructures.