High-pressure Hydrogen Production by Formic Acid Dehydrogenation

Abstract

This review reports recent progress in the use of formic acid (FA) as a hydrogen (H2) carrier with the author’s results. It shows both homogeneous and heterogeneous catalysts for the dehydrogenation of FA (FADH) with some selected catalysts designed for high-pressure gas production. Although FA can be readily generating H2 gas, thereby serving as an effective H2 carrier, the generated gas mixture includes H2 with 50 % CO2. This composition has presented challenges for applications such as in H2 fuel cells. However, certain catalysts, such as iridium complexes, can easily produce gases at the pressures over 100 MPa from FA, enabling the gas-liquid separation under high pressure conditions. This advantage has simplified the separation process for H2 and CO2. With these developments, the using formic acid as a H2 carrier has greatly increased with expectations for the future systems of H2 refueling stations. Additionally, the prospect of using separated liquid CO2 in various domains will be achieved sustainable chemical processing and energy solutions.