(560hs) Synthesis of Well-Defined Heterogeneous Catalysts Using Atomic Layer Deposition

Using Atomic Layer Deposition (ALD) to synthesize heterogeneous catalysts with atomic level precision has gained increasing interest in recent years. In our laboratory we have synthesized well-defined heterogeneous catalysts by depositing different noble metals onto various well-defined nanoparticle oxide shapes using ALD. The benefit of using well-defined oxide shapes is that the surface facets of each nanoparticle are well defined, as the CeO₂ octahedra have (111) surface terminations, the CeO₂ cubes expose (100) surface facets, while the rutile TiO₂ rods consist (110) surface facets. Therefore, this allows us to determine the influence of the support oxide surface structure on the active metal and ultimately on the probe reactions, which facilitates identifying structure-activity relationships for these catalyst materials. By using ALD during catalyst synthesis and tuning the ALD conditions, such as precursor temperature, deposition temperature and dose length, we have shown that we can carefully control the active metal loading on the nanoshapes. The resulting catalysts have been tested using CO oxidation and partial oxidation of alkanes as probe reactions.