Hydrogen gas could one day replace fossil fuels as a “clean” source of energy, producing only water and energy. However, handling large quantities of gaseous hydrogen is cumbersome and converting it to a liquid requires containers that can withstand extremely high pressures. Researchers are now getting in touch ACS Central Science have developed a method to store and release high-purity hydrogen with salts in the presence of amino acids.
The reversible storage of hydrogen in solid salts has emerged as a possible way to make the fuel easier to transport and handle, but the reactions to do this require noble metals as catalysts and can produce carbon dioxide as an unwanted by-product. Therefore, Henrik Junge, Matthias Beller and colleagues developed effective storage-release systems using bicarbonate and carbonate salts as well as manganese, a more common metal catalyst. The researchers found that converting bicarbonate and hydrogen to formate and vice versa was most effective using potassium salts, a manganese-based catalyst and lysine – an amino acid that acted as an additional promoter and reacted with carbon dioxide to scavenge it. at reaction temperatures below 200 F.
After five storage-release cycles, the reaction system produced hydrogen with high yield (80%) and purity (99%). The team also showed that carbonate salts and glutamic acid can be part of the reusable store-release system with hydrogen yields up to 94%. This technique paves the way for large-scale hydrogen storage in solids, say the researchers.
The authors acknowledge the funding from the state of Mecklenburg-West Pomerania and the European Union, the Leibniz program Cooperative Excellence K308/2020 (project “SUPREME”) and the European CO2PERATE project.
materials provided by American Chemical Society. Note: Content can be edited for style and length.