The electrifying effects of carbon-CeO2 interfaces in (electro)catalysis
Michele Melchionna, Manuela Bevilacqua, Paolo Fornasiero
Abstract
The exceptional and unique properties of cerium dioxide have encouraged scientists to exploit this material beyond its traditional role as a promoter in automotive engines. Electrochemical processes relevant to fuel cells, electrolyzers, and sensors can be facilitated or even directly catalyzed by the CeO2, whose redox properties are ideal for electrochemistry. However, given the insulating nature of pure ceria, the inclusion of conductive materials at the boundary with the metal oxide is necessary to boost the catalytic activity. Carbon in its various forms and morphologies is a dominant component in ceria-based electrocatalysts, significantly facilitating electron transfers and providing high surface area and improved stability. Moreover, given the improved electronic conductivity of reduced CeO2 in the wake of the decreased grain boundary impedance, the combination with a conductive component, such as carbon, can facilitate a reduction of the ceria.