HOMOGENEOUS CATALYTIC SYNTHESIS OF FORMIC-ACID (SALTS) BY HYDROGENATION OF CO2 WITH H-2 IN THE PRESENCE OF RUTHENIUM SPECIES

The purpose of this investigation is to synthesize formic acid by hydr ogenation of CO,. The catalysts or catalyst precursors employed in the se studies under 6 MPa(CO2/H-2) and at 60 degrees C, were ruthenium ch loride or ruthenium complexes. The turnover number obtained for formic acid production was ca. 200 by using ethanol/water (5:1) for a 5 h re action period. In the reaction mechanism the CO2 is activated by the r uthenium complex with formation of metal-formate intermediate HCO2RuH( CO)(PPh(3))(3), which releases formic acid by reductive elimination of the hydrido-formate ligands.