A HYDROGEN STORAGE SYSTEM BASED ON THE REVERSIBLE INTERCONVERSION BETWEEN H2/CO2 GAS AND FORMIC ACID IN WATER USING MOLECULAR CATALYSTS

摘要

A hydrogen economy provides an intriguing solution to the current and future "energy problem" because dihydrogen (H2) has many desirable features as a fuel and an energy carrier. However, the physical properties of H2 lead to safety issues as well as storage and transportation problems. An attractive solution to overcome these shortcomings is to store H2 using liquid phase chemicals such as formic acid (FA), which possess favorable stability and storage properties. Despite its relatively low hydrogen content (4.4 wt%), FA is non-toxic, bio-degradable, and is a liquid under ambient conditions, which renders it easy to store and transport. In the presence of appropriate catalysts, selective CO2 hydrogenation could catalytically generate FA, and dehydrogenation of FA could be performed to selectively form pressurized H2/CO2 mixtures. In a recent review article, the authors explain their view of why CO2 hydrogenation is an attractive alternative to its electro- and photochemical reduction.