Einsatz ligandenstabilisierter Nanopartikel in der heterogenen Katalyse

Abstract

Colloidally-synthesized nanoparticles are advantageous (e.g. control of size/morphology) compared to traditional synthetic routes. Although such particles are already been widely used in liquid phase catalysis, applications in heterogeneous gas phase catalysis are still largely missing. Whereas in many studies organic stabilizers from the synthesis are considered to block catalytically active sites, their benefits on heterogeneous gas phase catalysis are discussed in this work. Identical Pt nanoparticles with a variety of different ligands are synthesized with the ethylene glycol method which allows for a direct investigation of the influence of the ligands. Ligand-capped nanoparticles are deposited on different oxidic supports and compared with their ligand-free counterparts in respect to hydrogenation reactions and CO oxidation. The fate of the ligand shell in different temperature ranges and beneficial effects of the ligands on catalytic properties are elucidated. Furthermore, the results obtained for powder catalysts can be easily transferred to monolithic structures with distinct advantages for industrial applications.