Maximizing Activity and Stability by Turning Gold Catalysis Upside Down: Oxide Particles on Nanoporous Gold

Abstract

AbstractOxidation catalysis by gold spurred intensive research efforts over the last two decades, which is encouraged by the unparalleled activity at temperatures even below 0 °C. Yet, gold nanostructures are inherently prone to coalescence at elevated temperatures, which limits their application. We demonstrate that this impediment can be overcome by reversing the classical order, that is, by depositing oxide nanoparticles on a high‐surface area gold support. We used atomic layer deposition and liquid phase deposition, which leads to densely arranged oxide nanoparticles on the surface of a nanoporous gold material. In the case of a titania‐coated material, a catalyst with so far unprecedented high catalytic activity already at ambient temperatures and stability up to 600 °C could be obtained. We demonstrate its high catalytic potential for two important reactions in the context of exhaust gas treatment: the oxidation of CO and the reduction of NO already proceeding at ambient temperatures.