(377a) Co Particle ALD Facilitated On Metallic W ALD

Van Norman, S. A., University of Colorado Boulder
Weimer, A. W., University of Colorado Boulder
Falconer, J. L., University of Colorado Boulder

Efficient use of precious metal catalysts is essential to enhancing catalytic productivity.  Traditional catalyst impregnation proceeds through an oxide phase of the metal followed by reduction.  However, with traditional methods the metal is only partially reduced limiting the fraction of active material or the metal sinters under reduction conditions limiting active surface area.  The novel deposition of metallic phase Co particles and their properties is discussed.

In this study, metallic Co deposition is performed via a bi-molecular atomic layer deposition (ALD) reaction of cobaltocene and ammonia.  Surface adsorbed radicals are formed on a metallic W surface produced by ALD facilitate the reaction.  The radical interacts with the metal precursor resulting in chemically bonded Co to the surface.  Gas phase reaction is tracked via mass spectrophotometry.  Elemental analysis confirms deposition of Co.  Metal loading as a function of ALD cycles performed is also explored.  The reaction is also shown for oxide surfaces which do not show activity for metallic Co ALD under these conditions.