Tuning the Activity of Supported Nanoparticles Through Charge Transfer

This chapter shows how the affinity and hence, the activity of supported nanoparticles can be tuned by changing the charge on the catalyst surface. First, it illustrates this approach using alkali promoters, electrochemical promotion of catalysis (EPOC), and the application of an external electric field. Next, the chapter discusses the potential of exploiting the charge transfer between a semiconducting oxide support and metal nanoparticles. It aims to estimate the magnitude of this charge transfer using 1D metal-semiconductor contact theory and also discusses quantitative measurements of the charge transfer for Pt nanoparticles supported on ceria. The increased carrier concentration enhances charge transfer to the Pt particles and this enhances the CO oxidation activity of Pt/TiO2 under excess O2 conditions. The chapter further illustrates how the amount of charge transfer from the support can be tuned using techniques from defect engineering to controllably vary the activity of supported nanoparticles.