Menu
Home
People
Places
Arts
History
Plants & Animals
Science
Life & Culture
Technology
Reference.org
Heterogeneous gold catalysis
open-in-new
<p>Heterogeneous gold catalysis refers to the use of elemental <a href="/facts/Gold/1znknojp">gold</a> as a <a href="/facts/Heterogeneous_catalyst/ju7E0bab">heterogeneous catalyst</a>. As in most heterogeneous catalysis, the metal is typically <a href="/facts/Catalyst_support/zLpv8hJB">supported</a> on metal oxide. Furthermore, as seen in other heterogeneous catalysts, activity increases with a decreasing diameter of supported gold clusters. Several industrially relevant processes are also observed such as H2 activation, <a href="/facts/Water-gas_shift_reaction/sorqPcSn">Water-gas shift reaction</a>, and <a href="/facts/Hydrogenation/l7EzNSA7">hydrogenation</a>. One or two gold-catalyzed reactions may have been commercialized. </p><p>The high activity of supported gold clusters has been proposed to arise from a combination of structural changes, quantum-size effects and support effects that preferentially tune the <a href="/facts/Electronic_structure/RuHwQWfp">electronic structure</a> of gold such that optimal binding of adsorbates during the catalytic cycle is enabled. The selectivity and activity of gold nanoparticles can be finely tuned by varying the choice of support material, with e.g. <a href="/facts/Titanium_dioxide/T0KWmKcz">titania</a> (TiO2), <a href="/facts/Hematite/716YBzGr">hematite</a> (α-Fe2O3), <a href="/facts/Cobalt(II,III)_oxide/lp55FCdw">cobalt(II/III) oxide</a> (Co3O4) and <a href="/facts/Nickel(II)_oxide/r3qlMkJB">nickel(II) oxide</a> (NiO) serving as the most effective support materials for facilitating the catalysis of CO combustion. Besides enabling an optimal dispersion of the nanoclusters, the support materials have been suggested to promote catalysis by altering the size, shape, strain and charge state of the cluster. A precise shape control of the deposited gold clusters has been shown to be important for optimizing the catalytic activity, with hemispherical, few atomic layers thick nanoparticles generally exhibiting the most desirable catalytic properties due to maximized number of high-energy edge and corner sites. </p>