Continuous Hydrogen Generation from Formic Acid: Highly Active and Stable Ruthenium Catalysts

The ruthenium‐catalyzed decomposition of formic acid was investigated with respect to continuous hydrogen generation and long‐term stability of the catalytic systems. A highly active and stable system is presented, which was studied in batch and continuous modes for up to two months. The optimized catalyst system containing N,N ‐dimethyl‐ n ‐hexylamine with an in situ generated catalyst from (benzene)ruthenium dichloride dimer [RuCl 2 (benzene)] 2 and 6 equivalents of 1,2‐bis(diphenylphosphino)ethane (dppe) reached at room temperature a total turnover number (TON) of approximatly 260,000 with average turnover frequency (TOF) of about 900 h −1 . Only hydrogen and carbon dioxide were detected in the produced gas mixture which makes this system applicable for direct use in fuel cells.