Reversible Hydrogen Storage using CO2 and a Proton-Switchable Iridium Catalyst in Aqueous Media
Green plants convert carbon dioxide to sugar for energy storage via photosynthesis. We investigated a novel catalyst that uses carbon dioxide and hydrogen to store energy as formic acid. Using a homogeneous Ir catalyst with a proton responsive ligand, we have achieved the first reversible and recyclable hydrogen storage system that operates under mild conditions using CO2, formate and formic acid. This system is energy-efficient and green because it operates near ambient conditions, uses water as a solvent, produces high-pressure CO-free hydrogen, and uses pH to control hydrogen production or consumption. The extraordinary and switchable catalytic activity is attributed to the multifunctional ligand which acts as a proton-relay and strong p-donor, and is rationalized by theoretical and experimental studies.
Last Modified: September 13, 2012