文摘
The selective dehydrogenation of aqueous solutions of HCOOH/HCOONa to H2 and CO2 gas mixtures has been investigated using RuCl3路3H2O as a homogeneous catalyst precursor in the presence of different monoaryl-biaryl or alkyl-biaryl phosphines and aryl diphosphines bearing sulfonated groups. All catalytic systems were used in water without any additives and proved to be active at 90 掳C, giving high conversions and good TOF values. As an alternative Ru(II) metal precursor, the known dimer [Ru(畏6-C6H6)Cl2]2 was also tested as in situ catalyst with selected phosphines as well as an isolated Ru(II)-catalyst with one of them. By using high-pressure NMR (HPNMR) techniques, indications on the nature of the active species involved in the catalytic cycles were obtained.
Keywords:
aqueous-phase catalysis; formic acid; hydrogen generation; ruthenium; sulfonated phosphines