Non-colloidal Nanocatalysts Fabricated with Nanolithography and Arc Plasma Deposition

Abstract

In this chapter, we discuss the most recent advances in the preparation of nanocatalysts via dry processes. We describe the fabrication of metal nanoparticles using lithography and the synthesis of catalytic nanoparticles using non-colloidal techniques, including plasma deposition and lithographical techniques. Synthesis of oxide-supported metal catalysts via wet-chemical processes is well known in heterogeneous catalysis [1–3]. Impregnation, coprecipitation, deposition-precipitation, ion exchange, sol–gel, and colloidal processes are typical examples of wet processes. Typically, precursors of the active catalyst materials are dissolved and reacted in an aqueous or organic solution and the solution is mixed with ceramic supports to prepare the oxide-supported metal catalysts. In general, the wet-chemically produced oxide-supported metal catalysts need to undergo annealing processes at elevated temperature in order to eliminate the organic materials required for the wet processes, such as solvent, surfactant, or capping agents [4–6]. The annealing process can cause oxidation of the catalyst metal particles, causing catalytic activity deterioration. In order to overcome the shortcomings of wet-chemical processes, direct vaporization of metallic materials to deposit active materials on ceramic supports has drawn considerable interest due to its simplicity, high reproducibility, and the possibility for large-scale production. Examples of such dry synthesis processes for nanocatalyst production are arc plasma deposition (APD) [7–9], e-beam lithography [10, 11], and laser vaporization [12, 13]. In this chapter, we introduce APD and nanolithography technologies for preparing catalyst materials and discuss recent advances in their application.