High Pressure Process Group, Department of Chemical Engineering and Environmental Technology, BioEcoUva Research Institute on Bioeconomy, Universidad de Valladolid, 47011 Valladolid, Spain.
Molecules. 2022 Mar 2;27(5):1652. doi: 10.3390/molecules27051652.
High-temperature water reactions to reduce carbon dioxide were carried out by using an organic reductant and a series of metals and metal oxides as catalysts, as well as activated carbon (C). As CO2 source, sodium bicarbonate and ammonium carbamate were used. Glucose was the reductant. Cu, Ni, Pd/C 5%, Ru/C 5%, C, Fe2O3 and Fe3O4 were the catalysts tested. The products of CO2 reduction were formic acid and other subproducts from sugar hydrolysis such as acetic acid and lactic acid. Reactions with sodium bicarbonate reached higher yields of formic acid in comparison to ammonium carbamate reactions. Higher yields of formic acid (53% and 52%) were obtained by using C and Fe3O4 as catalysts and sodium bicarbonate as carbon source. Reactions with ammonium carbamate achieved a yield of formic acid up to 25% by using Fe3O4 as catalyst. The origin of the carbon that forms formic acid was investigated by using NaH13CO3 as carbon source. Depending on the catalyst, the fraction of formic acid coming from the reduction of the isotope of sodium bicarbonate varied from 32 to 81%. This fraction decreased in the following order: Pd/C 5% > Ru/C 5% > Ni > Cu > C ≈ Fe2O3 > Fe3O4.
采用有机还原剂和一系列金属和金属氧化物作为催化剂，并使用活性炭（C）进行高温水反应以还原二氧化碳。以碳酸氢钠和氨基甲酸铵作为 CO2 源，葡萄糖作为还原剂。测试了 Cu、Ni、Pd/C（5%）、Ru/C（5%）、C、Fe2O3 和 Fe3O4 等催化剂。CO2 还原的产物为甲酸和糖水解的其他副产物，如乙酸和乳酸。与氨基甲酸铵的反应相比，碳酸氢钠的反应生成了更高产率的甲酸。使用 C 和 Fe3O4 作为催化剂，以碳酸氢钠作为碳源，可得到 53%和 52%的甲酸高收率。使用 Fe3O4 作为催化剂，通过与氨基甲酸铵的反应可得到高达 25%的甲酸产率。通过使用 NaH13CO3 作为碳源，研究了形成甲酸的碳的来源。根据催化剂的不同，碳酸氢钠同位素还原生成的甲酸的比例从 32%到 81%不等。该比例按以下顺序降低：Pd/C（5%）>Ru/C（5%）>Ni>Cu>C≈Fe2O3>Fe3O4。
