The growth of Pt-Pd nanoparticles from organometallic precursors is studied in situ in real time by HRTEM in a graphene oxide liquid cell. The reduction of the metal precursors is induced by the electron beam. During the growth, the particles rearrange their internal structure to form faceted single crystals. The growth is compatible with the Lifshitz-Slyozov-Wagner (LSW) mechanism in the limiting case of a reaction-limited process. The same particles are also synthesized ex situ by using a chemical reducing agent and observed in HRTEM.
Keywords: HRTEM in a liquid cell; Pt−Pd; in situ growth; nanoalloys.