Strong metal–support interactions on gold nanoparticle catalysts achieved through Le Chatelier’s principle

Strong metal–support interactions (SMSIs) are crucial for the preparation of supported metal catalysts. A prevailing view is that the redox feature of the metal oxide support is the driving force behind SMSI construction. Herein we demonstrate CO2-induced SMSIs between irreducible oxide MgO and noble gold nanoparticles, presenting electronic and geometric features that are similar to those of classical SMSIs. The key to these interactions is activating the oxide surface by a reversible reaction, MgO + CO2 ⇆ MgCO3, which leads to migration of the support onto the gold nanoparticles to form thin overlayers. The overlayer is permeable to the reactant molecules, stable under the oxidation conditions and even water tolerant, resulting in sinter-resistant gold nanoparticle catalysts. This investigation provides an approach for the rational design and optimization of supported metal catalysts based on irreducible oxides, and deepens our understanding of the mechanism of SMSI formation. The strong metal–support interaction is an important phenomenon for the modulation of a catalyst´s performance but is traditionally restricted to reducible oxide supports. Here, a CO2-induced strong metal–support interaction is reported for gold nanoparticles supported on non-reducible MgO to yield a superior oxidation catalyst.