Clay-based SiO2 as active support of gold nanoparticles for CO oxidation catalyst: Pivotal role of residual Al

SiO2 is generally regarded as an “inert” support of gold catalysts for CO oxidation. We find that silica obtained from a natural clay mineral can be used as excellent gold-support for efficient CO oxidation at relatively low temperature. Fine Au particles are found to locate around the Al sites, rather than on pure SiO2 area. Accordingly, high Au loading and catalytic activity for the clay-based SiO2 supports are ascribed to the residual aluminum originally from the clay.

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► SiO2 from a natural clay can be used as excellent Au-support for efficient CO oxidation.
► The prepared catalysts have notable Au loading and considerable oxidation activity.
► The fine Au particles are found to locate around the Al sites.
► Al sites are able to help to form and stabilize Au nanoparticle on surface.