KSEF RDE: Nanoporous Nickel as an Alternative to Raney Nickel

The combination of structure (including a high surface-to-volumc ratio), hydrogen absorption ability and high catalytic activity at room temperature makes nanoporous Ni (np-Ni) an excellent heterogeneous catalyst. It is used commercially as Raney Ni (RN) in fine powder fonn, exhibiting pore diameters as small as 2 nm. Activated RN is highly pyrophoric and must be protected from air exposure, for example by preparing as a water-based slurry, to prevent ignition of hydrogen gas contained in the porous structure. Additionally, while some research has been performed on making bulk or foil forms of RN, available processes are unable to produce crack-free RN materials with structural integrity. The research objective of this proposal is to fabricate, structurally characterize and mechanically test crack-free np-Ni as an alternative to RN with improved stability. This will entail the determination of optimal alloy composition and processing conditions for thin film np-Ni. A systematic study of thin film mechanical behavior (using wafer curvature and thin film damping) will be perfonned for np-Ni with varying ligament width and film thickness. Finally, the chemical behavior ofnp-Ni will be evaluated, for cxamp1e in hydrogenation reactions. Completion of these objectives will provide nanoscale Ni with improved mechanica1 integrity and optimized properties for structural and catalysis applications. Ultimately, this np-Ni material may be used in place of sintered RN coatings in applications such as a membrane reactor. This study will develop a practical material (np-Ni) that may be an economic alternative to Raney Ni for certain catalysis applications and will also provide fundamental scientific understanding of nanoscale defonnation, including geometric size effects. This project will contribute to energy-rclated research activities at the University of Kentucky, and will serve as a basis for additional proposals to DOE.