High-pressure H2 was produced by the selective dehydrogenation of formic acid (DFA) using ruthenium complexes at mild temperatures in various organic solvents and water. Among the solvents studied, 1,4-dioxane was the best candidate for this reaction to generate high gas pressure of 20 MPa at 80 °C using the Ru complex having a dearomatized pyridine-based pincer PN3P* ligand. This complex shows reusability for the high-pressure DFA in 1,4-dioxiane while maintaining the catalytic performance, however, deactivation occurred in other solvents. In dimethyl sulfoxide, its decomposition products may cause catalytic deactivation. The gas pressure generated in 1,4-dioxane was lower than that in water due to the high dissolution of 1,4-dioxane into CO2 according the vapor-liquid equilibrium calculations. The role of solvent is crucial since it affected the catalytic performance and also the generated gas pressure (H2 and CO2) from FA.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: M.I. and H.K. would like to acknowledge Dr. Maya Chatterjee for help with the manuscript preparation. This work was supported by the Japan Science and Technology Agency (JST), CREST (No. JPMJCR1342), and the International Joint Research Program for Innovative Energy Technology of the Ministry of Economy, Trade, and Industry (METI) of Japan for M.I. and H.K., and by King Abdullah University of Science and Technology for C.G. and K.-W.H