Iridium-Catalyzed Continuous Hydrogen Generation from Formic Acid and Its Subsequent Utilization in a Fuel Cell: Toward a Carbon Neutral Chemical Energy Storage

Abstract

This study represents a notable step toward a potentially carbon neutral energy storage solution based on formic acid as a hydrogen/energy carrier. A catalytic system derived from IrCl3 and 1,3-bis(2′-pyridyl-imino)-isoindoline (IndH) in the presence of aqueous sodium formate showed high selectivity and robustness for hydrogen generation from formic acid (FA) at 90–100 °C under both high and moderate pressure conditions suppressing the formation of CO impurity. Being a solid substance, the catalyst can be recovered by a simple filtration, if necessary. Furthermore, addition of neat formic acid is sufficient to reuse the catalyst and maintain a constant flow of H2 and CO2 mixture and the stable performance of a coupled fuel cell. The easy to recycle catalyst did not show any loss of activity after 20 days of continuous use, and similar activity was observed even a year after the original preparation. The reactor for formic acid decomposition provided a one to one ratio of a H2/CO2 mixture that was coupled ...