Gold nanoparticle-catalyzed reduction in a model system: Quantitative determination of reactive heterogeneity of a supported nanoparticle surface

► A silica-supported Au nanoparticle catalyst is used for resazurin reduction. ► One percentage of the surface atoms accounts for 30% of the catalyst's activity. ► Kinetic poisoning experiments reveal two different types of active sites. ► The catalytically active sites are suggested to be corner and edge atoms. ► More than an order of magnitude difference in activity is shown between sites.