(575z) Synthesis of Well-Defined Multilayer Catalyst Systems by Successive Ionic Layer Deposition

Metal-support interfaces in many catalyst systems are believed to be particularly active catalytic sites. However, the complexity of typical supported catalyst systems makes it difficult to isolate the effects of the metal-support interactions. Successive Ionic Layer Deposition (SILD) is an aqueous technique that enables the organized synthesis of well-defined catalytic systems.

In SILD, submonolayers of aqueous cations and anions are sequentially adsorbed on a support. Aqueous metal salts are used as cationic precursors and weak bases used to as anionic precursors to deposit metal oxides. The parameter space of tunable variables available for SILD allows for significant control over the chemistry and morphology of the deposited materials at the nanometer scale.

It has been reported that a dispersed phase of BaO on Al2O3 plays a major role in NOx emission control catalysis for lean burn engines. This suggests that the interface between the barium oxide and the aluminum oxide may be particularly more reactive than the bulk-like barium oxide. However, conventional catalyst synthesis techniques tend to produce both bulk-like and dispersed phases of BaO supported on Al2O3. SILD offers the opportunity to exclusively produce the dispersed phase of BaO on Al2O3 and study its catalytic performance. In this poster, we describe how SILD was used to synthesize a dispersed phase of BaO on Al2O3.