Hongwei Yan,* Christopher F. Blanford,* Brian T. Holland,*

Michael Parent,^† William H. Smyrl,^† Andreas Stein*

*Department of Chemistry, University of Minnesota, 207 Pleasant St. SE, Minneapolis, MN 55455

Abstract

Here we report a general procedure of synthesizing macroporous metals with 250-500 nm monodisperse voids surrounded by nanocrystalline metal walls. The method is based on templated precipitation and subsequent chemical conversion of the precursors to a macroporous metal or metal oxide. The metal oxide can be further converted to a purely metallic, ordered macroporous solid by complete reduction in hydrogen or to a mixed metal oxide/metal composite by partial reduction. With pore sizes of a few hundred nanometers, these materials fill a gap in the range of accessible pore sizes between microporous (Raney nickel) or mesoporous metals (prepared from liquid crystalline phases) on the smaller end (< 10 nm), and metal foams on the larger end (> 100s of µm). Whereas access to the high surface area in materials such as Raney nickel is diffusion limited, the surface of the macroporous nickel presented here is more easily accessible through the large void spaces. As a result, improved performance may be possible in applications such as porous electrodes or supports for solid electrolytes.