Iodide as Terminating Agent for Platinum Electrodeposition

Approximate Pt layers hold great promise to be highly active and durable oxygen reduction reaction (ORR) catalysts. Electrodeposition of such layers on relevant catalyst supports, for example TiOx, requires the application of a Pt-on-Pt deposition limiter to keep layers thin and leave no atom behind for catalysis. Classic Pt-on-Pt deposition limiting agents like CO and over-potential deposited hydrogen (H-opd) work reliably on gold but fail on TiOx substrates. Iodide, in contrast, is a new Pt-on-Pt deposition limiting agent that shows substantial Pt layer thickness reduction during electrodeposition on gold as well as TiOx substrates.