Formic acid is well known as a hydrogen source and a hydrogen donor under thermal, catalytic and photocatalytic conditions. In this study, we generate hydrogen and carbon dioxide in a ratio of 1:1 by decomposing formic acid in presence of a homogeneous ruthenium catalysis under mild conditions. At 40oC TOF>600 h−1 was realized. The catalyst is stable and robust through numerous cycles of the decomposition reaction. Furthermore, maintaining the active catalyst system under ambient conditions for months caused no harm to its vitality. The catalytic activity could be restored instantly at any time simply by adding formic acid and heating to 40oC. Over the years, scientists have suggested different incomplete schemes for the decomposition reaction based on experimental and theoretical studies. In this paper we propose a novel molecular mechanism for this reaction.

Formic acid and its salts are an alternative source for hydrogen generation. In this study, we store hydrogen using the formate–bicarbonate cycle. Aqueous sodium bicarbonate is hydrogenated to form sodium formate, which can then be decomposed to release hydrogen and sodium bicarbonate. The hydrogenation step is carried out under mild conditions in the presence of a homogeneous ruthenium catalyst. Hydrogen charge is realized at 70 °C under a hydrogen pressure of 20 bar, achieving yields > 80% and turnover number > 610. The catalyst is stable and robust through numerous cycles of the hydrogenation reaction. The formate ion formed during the bicarbonate hydrogenation is assayed and quantified by ion chromatography.

The ruthenium (cis‐RuCl2(DPPM)2) based catalytic dehydrogenation reaction of formic acid in the presence of an amine base in a biphasic system experimentally tested by Treigerman and Sasson (ChemistrySelect 2017, 2, 5816) was studied computationally to ascertain its mechanism. The energy span model was applied on the double‐hybrid DFT computed energy profile to comprehend its kinetics. The catalytic network includes three possible interconnected cycles depending on the ancillary ligands, going through decarboxylation, protonation and H2 release. The dihydride cycle proves to be the most efficient after pre‐activation steps coming from the other cycles. The turnover frequency (TOF) determining intermediate (TDI) is the formatohydride species, while the TOF determining transition state (TDTS) corresponds to a formate decarboxylation. Herein we include the effect of reactants concentrations to the energy span model, which proved to be essential to comprehend the experimental ESI‐MS results and to propose a more accurate mechanism.

Formic acid is recognized as a promising hydrogen carrier. It readily decomposes to release hydrogen (and carbon dioxide) in the presence of apposite catalysts. The main deficiency of this practice is that the reverse reaction, the hydrogenation of carbon dioxide to formic acid is an uphill reaction necessitating extreme conditions. Carbon dioxide should be converted to bicarbonate salts since their hydrogenation is reasonable for storing hydrogen. The related approach has a drawback as formate salts are produced. The latter has lower weight percentage of hydrogen and they must be converted to formic acid. The goals of our research were to separate formate salt from the reaction mixture and to convert it to formic acid. In this paper, we present a process that combines the advantages of both methodologies-formic acid is the carrier, but the hydrogen is charged to a bicarbonate ion. This stage completes the formic acid cycle (FAC), which could operate as a continuous process for the production and storage of hydrogen. Additional research, including proper rescaling and optimization, should be carried out in order to assess the potential of such a process as a basis for replacing the present day combustion of fossil fuels with hydrogen usage in fuel cells.

Hydrogen is recognized as an ultimate fuel due to its clean burning and its capacity to convert chemical energy to electricity and vice versa. Nonetheless, hydrogen is also known as a hazardous material which entails strict compliance with safety regulations. Consequently, numerous research laboratories are seeking for safe chemical and physical methods for hydrogen storage. Formic acid which is evidently an attractive hydrogen carrier can be decomposed to hydrogen and carbon dioxide in a catalytic reaction. The main disadvantage of this reaction is the carbon dioxide emission. In this study, we present an alternative method to capture carbon dioxide from the gas stream. Furthermore, we suggest a pathway for storing the hydrogen that was produced.