Solidification microstructure of Raney® metal catalyst alloys

COLL 80

Kevin Trumble and Mi-hee Choi. School of Materials Engineering, Purdue University, W. Lafayette, IN 47907
Raney® metal catalysts are the produced by caustic leaching of multi-phase aluminide intermetallics based primarily on the Al-Ni, Al-Co, Al-Fe, and Al-Cu systems. Although they represent the main catalyst for hydrogenation and other reactions, comparatively little is known about their parent alloy microstructure and its effects on the leaching processing and resulting catalyst performance. The parent alloys typically exhibit complex solidification paths involving multiple peritectic transformations, resulting in non-equilibrium, multi-phase microstructures. Alloys produced by induction melting and casting in metal molds have been characterized using optical microscopy and quantitative stereology in combination with x-ray diffraction. As-cast and annealed microstructures of the relevant parent alloys in the systems Al-Ni, Al-Co, and Al-Fe will be compared with the available phase equilibria predictions. Preliminary results on in-situ leaching of Al-Co alloys using environmental-SEM will be discussed in the context of modeling the leaching kinetics.

Raney® is a registered trademark of W.R. Grace & Co. This work has been supported in part by DuPont, ConocoPhillips, and Purdue University.