PNNL

Abstract

In this perspective article the synthesis and thermodynamic properties of aqueous solutions of formate salts (FS, HCO2-) are described in relationship to the concept of hydrogen carriers. The physiochemical properties of solid FS, aqueous formate solutions and aqueous bicarbonate solutions set the limitations for storage capacity, deliverable capacity and usable hydrogen capacity of these hydrogen carriers respectively. These parameters will help in the design of systems that utilize hydrogen carriers for storage and transport of hydrogen for fuel cell power applications. FS, as well as admixtures with formic acid (FA, H2CO2) have potential to address the goals outlined in the Department of Energy’s H2@scale initiative: to store significant quantity of energy (hundreds of megawatts) obtained from large scale renewable resources in chemical bonds.