Formic Acid to Power towards Low‐Carbon Economy

Abstract

The corresponding global annual carbon dioxide (CO 2 ) emissions had also increased from 23.1 gigatonnes of CO 2 (Gt CO2 ) in 2000 to 33.2 Gt CO2 in 2018. The excessive reliance on fossil fuels has caused the atmospheric CO 2 concentration to increase from the pre-industrial 280 ppm in the 18th century to the annual average of more than 410 ppm nowadays, which is found to be positively correlated to climate change. [2] To alleviate the environmental issues and to find viable alternatives for depleting fossil fuel reserves, the development and largescale deployment of clean and sustainable energy systems is of utmost importance. The development of suitable energy carriers is necessary to enable energy storage and distribution and to overcome the deficiency due to the intermittency of renewable energy sources such as solar and wind power. The use of H 2 has a great potential to diversify energy sectors and to prepare for the future implementation of low-carbon electricity and renewable energy. H 2 fuel cell (FC) technology is considered mature and regarded as the only technology to realize mobility without change of habits. As stated in the 2019 report by International Energy Agency to G20, H 2 is expected "to play a key role in a clean, secure and affordable energy future." [3] However, due to the lack of viable technologies for safe, efficient, and economical storage and transportation of H 2 , the applications of hydrogen have significantly been limited. [4] The storage and utilization of low-carbon electricity and decarbonization of transportation are essential components for the future energy transition into a low-carbon economy. While hydrogen has been identified as a potential energy carrier, the lack of viable technologies for safe and efficient storage and transportation of H 2 greatly limits its applications and deployment at scale. Formic acid (FA) is considered one of the promising H 2 energy carriers because of its high volumetric H 2 storage capacity of 53 g H 2 /L, and relatively low toxicity and flammability for convenient and low-cost storage and transportation. FA can be employed to generate electricity either in direct FA fuel cells (FCs) or indirectly as an H 2 source for hydrogen FCs. FA can enable large-scale chemical H 2 storage to eliminate energy-intensive and expensive processes for H 2 liquefaction and compression and thus to achieve higher efficiency and broader utilization. This perspective summarizes recent advances in catalyst development for selective dehydrogenation of FA and high-pressure H 2 production. The advantages and limitations of FA-to-power options are highlighted. Existing life cycle assessment (LCA) and economic analysis studies are reviewed to discuss the feasibility and future potential of FA as a fuel.

Iron Dihydride Complex Stabilized by an All-Phosphorus-Based Pincer Ligand and Carbon Monoxide

“…Significant activity was observed for the catalytic dehydrogenation of HCO 2 H to CO 2 . Studying this process was motivated by the promise of using formic acid as a hydrogen storage material, and a number of iron-based catalysts have been developed, including several featuring a PNP-pincer ligand. ,, For PPP-pincer systems, a cobalt hydride complex, ( Cy PP NHCH 2 Ph P)­Co­(CO)­H, has also been studied specifically for this transformation . Despite the progress made in this research area, there are many practical aspects that have not been fully addressed (e.g., costs, efficiencies, and sensitivity to impurities), and the development of new catalytic systems is needed.…”

Electrochemical Reduction of CO2 to Formate on Nanoparticulated Bi−Sn−Sb Electrodes

“…Among them, formic acid (HCOOH) is an important raw material for processing pharmaceutical and chemical products. Moreover, HCOOH is a liquid fuel for proton‐exchange membrane fuel cells [7] . Due to the ability to store hydrogen in liquid form, HCOOH is one of the most economically viable products during CO 2 electroreduction process [8] .…”

“…Moreover, HCOOH is a liquid fuel for proton-exchange membrane fuel cells. [7] Due to the ability to store hydrogen in liquid form, HCOOH is one of the most economically viable products during CO 2 electroreduction process. [8] Specific catalysts are required for the selective CO 2 conversion towards HCOOH.…”

A Low-Coordinate Iridium Complex with a Donor-Flexible O,N-Ligand for Highly Efficient Formic Acid Dehydrogenation

“…The implementation of such catalytic systems is, however, often hampered by the requirement of sophisticated and expensive ligands to impart high catalytic activity. 23 Here we demonstrate the benefit of a new class of readily accessible low-cost nitrogen-based ligands to develop dehydrogenation catalysts with outstanding activity and stability. The ligand design is based on a phenoxy-substituted pyridylidene-amine (PYE).…”