Efficient And Reversible Catalysis Of Formic Acid-Carbon Dioxide Cycle Using Carbamate-Substituted Ruthenium-Dithiolate Complexes

It is important to develop viable technologies for efficient hydrogen (H-2) production and carbon dioxide (CO2) conversion to realize the future supply of clean energy and reduction of global CO2 concentration. Herein, we report a series of carbamate-substituted ruthenium-dithiolate complexes 1-3, [Ru-x(CO)(y)(mu-SCH(NCO2(C(CH3)(3)))CH2CH2S)] (x=2, 3, 6 and y=6, 9, 20), which can effectively catalyze the reversible formic acid-carbon dioxide (FA-CO2/H-2) cycle that can be used to convert CO2 and produce H-2. Complex 2 effectively dehydrogenates FA to produce H-2 with an unprecedented turnover frequency (TOF) of 1.15x10(6) h(-1) under conditions of sunlight irradiation. Under conditions of high temperature and pressure, complex 3 hydrogenates CO2 to FA with a high initial TOF of 1.02x10(6) h(-1), resulting in an efficient FA-CO2/H-2 cycle. These results can potentially help provide the platform for the development of technologies that can be used in future to produce clean energy and control environmental threats.