Electrochemical promotion of catalysis: mechanistic investigations and monolithic electropromoted reactors

Recent progress is surveyed both in elucidating the mechanism of electrochemical promotion at the molecular level and in utilizing it in monolithic electropromoted catalytic reactors. On the mechanistic side, recent 18O2 TPD and 18O2 + CO TP reaction studies have confirmed, together with STM, the validity of the sacrificial promoter model for both electrochemical promotion and metal-support interactions of Pt and Rh with anionic (YSZ) and mixed anionic-electronic supports. On the practical side, two recent advances are discussed, i.e., the electropromotion of thin (40 nm) sputtered catalyst films, with metal dispersion of the order of 20%, and the development of the monolithic electropromoted reactor (MEPR) which is a hybrid between a monolithic catalytic reactor and a flat-plate solid oxide fuel cell and allows for compact design and easy scale-up and scale-down of electropromoted catalytic units.