Electrocatalytically Active Silver Organic Framework: Ag(I)-Complex Incorporated in Activated Carbon

Silver is known as a viable alternative for platinum group metals for the catalysis of the oxygen reduction reaction in alkaline electrolyte. Unlike most other platinum-group metal-free catalysts, usually organo-metallic complexes, silver is commonly used in its metallic form (Ag(0)). Herein, we describe the preparation, characterization, and electrochemical activity of a unique silver-based catalyst, based on Ag(I) ions coordinated to oxygen groups in an organic ligand (benzene tricarboxylic acid - BTC) which forms a metal organic framework, similar to first-row transition metal-based catalysts in metal organic frameworks. When the silver-based catalyst is incorporated in a porous carbon support, it exhibits high electrocatalytic activity for the oxygen reduction reaction, with a distinct electrochemical behavior, different than metallic silver. In addition, the use of the ionic form of the silver, which is atomically dispersed, allows to lower its loading of the metal by at least one order of magnitude when compared to other reported silver-based oxygen reduction reaction catalysts.