10 - Metallic nanoparticles for catalysis applications

Abstract

Noble metals alloyed with certain transition metals in the form of a nanoalloy exhibit enhanced catalytic or electrocatalytic activities for a number of oxidation reactions. This chapter discusses some important insights into how the interatomic distances and structures of the nanoalloy catalysts operate synergistically in activating oxygen and maneuvering surface oxygenated species by highlighting examples of nanoalloy catalysts in which Pt or Pd is alloyed with a second and/or third transition metal (M/M′=Co, V, Ni, Cu) for catalytic oxidation of carbon monoxide in gas phase and electrocatalytic oxidation of alcohols in an electrolyte. One important emphasis is placed on understanding atomic-scale chemical/structural ordering and coordination in correlation with the catalytic or electrocatalytic properties based on findings from ex situ and in situ synchrotron X-ray techniques such as high energy X-ray diffraction coupled to atomic pair distribution function and X-ray absorption fine structure spectroscopic analysis. The understanding of the detailed active sites of the nanoalloys has significant implications for the design of low-cost, active, and durable catalysts for sustainable energy production and conversion reactions.