PNNL

Abstract

The development of thermally stable, nanometer-sized precious metal based catalysts remains a daunting challenge. Such materials, especially those based on the use of costly platinum metal, are essential and, to date, non-replaceable for a large number of industrially important catalytic processes. Here we report a well-defined cuboctahedral MgAl2O4 spinel support material that is capable of stabilizing platinum particles in the range of 1-3 nm on its relatively abundant {111} facets during extremely severe aging at 800°C in air for 1 week (168 h). The aged catalysts retain platinum dispersions of 15.9% with catalytic activities for methanol oxidation approximately 80% of fresh ones, while a conventional Pt/?-Al2O3 catalyst is severely sintered and nearly inactive. We reveal the origin of the markedly superior ability of spinel {111} facets, resulting from strong interactions between spinel surface oxygens and epitaxial platinum {111} facets, inspiring the rational design of anti-sintering supported platinum group catalysts. This work was supported by U. S. Department of Energy (DOE), Office of Basic Energy Sciences, Division of Chemical Sciences, Biosciences and Geosciences. The research was performed in the Environmental Molecular Sciences Laboratory, a national scientific user facility sponsored by the DOE Office of Biological and Environmental Research, and located at Pacific Northwest National Laboratory. PNNL is operated for DOE by Battelle.