Formic
acid is a liquid, safe, and energy-dense carrier for fuel
cells. Above all, it can be sustainably produced from the electroreduction
of CO2. The formic acid market is currently saturated,
and it requires alternative applications to justify additional production
capacity. Fuel cell technologies offer a chance to expand it, while
creating an opportunity for sustainability in the energy sector. Formic
acid-based fuel cells represent a promising energy supply system in
terms of high theoretical open-circuit voltage (1.48 V). Compared
to common fuel cells running on H2 (e.g., proton-exchange
membrane fuel cells), formic acid has a lower storage cost and is
safer. This review focuses on the sustainable production of formic
acid from CO2 and on the detailed analysis of commercial
examples of formic acid-based fuel cells, in particular direct formic
acid fuel cell stacks. Designs described in the literature are mostly
at the laboratory scale, still, with 301 W as the maximum power output
achieved. These case studies are fundamental for the scale-up; however,
additional efforts are required to solve crossover and increase performance.