Gold has long been considered an ‘inert’ metal. However, catalysis by gold has rapidly become a hot topic in chemistry after the discovery that nano-scale gold is highly active for CO oxidation even at room temperature which is not possible by other metals. The applications of gold catalysts have been extended to hydrogenation, epoxidation, alcohols and aldehydes oxidation, and even aerobic oxidation of alkanes. Several mechanisms have been proposed mainly based on the study of CO oxidation, but the nature of the active Au species/structure/site remains obscure.

In this work, by designing several gold catalysts and comparing their activities in the aerobic oxidation of benzyl alcohol, I found the crystal facet structure of the MgO support has a significant impact on the activities of gold nanoparticles and the Au-support interface can influence the thermal stability of gold nanoparticles and thus their activities at high temperature. My experimental results support the proposal that:​ the electronic effects of the Au-support interface strongly influences the catalytic activity. The electronic effect can be enhanced by increasing the contact interface or choosing electron rich supports such as those with highly polar surfaces or rich in vacancies.

I also realized in my Ph.d research that gold/metal oxide is a complex catalysis system. The nature of metal oxides, the crystal facet of metal oxides, the vacancies on metal oxides, the surface area of metal oxides, the interface between gold and metal oxides, the shape and size of gold nanoparticles all play important roles. Even I tried my best to keep other factors identical when study on one factor, the influence from other factors cannot be absolutely excluded from the results. That is a common problem faced by all research groups. However, that is also the reason why gold/metal oxides catalysts can attract so much attention from scientists from all over the world.