Homogenous catalytic hydrogenation of bicarbonate with water soluble aryl phosphine ligands

• The reactions were monitored by high pressure NMR (HPNMR) spectroscopy.
• The different behaviors could be related to variations in air stabilities of the ligands.
• The effect of the stability and recyclability of the catalytic systems is discussed.

The chemical transformation of CO2 and bicarbonates into useful products becomes increasingly important as the atmospheric CO2 level has reached 400 ppm. Here a small library of sulfonated aryl monophosphines and aryl diphosphines was tested as stabilizing ligands for a ruthenium catalytic precursor in aqueous-phase bicarbonate hydrogenation to formate. The reactions were monitored by high pressure NMR (HPNMR) spectroscopy which also revealed the presence of stable hydride species possibly linked to the superior activity of certain ligands. The different behaviors observed could be related to variations in air stabilities of the ligands. In some cases a pre-activation step of the catalytic precursor was necessary. The effect of such parameters on the stability and recyclability of the catalytic systems is discussed.

The activity of in situ formed catalytic systems in the bicarbonate hydrogenation reaction is evaluated. Several stabilizing water soluble phosphine ligands were tested in the presence of ruthenium catalyst precursors.Figure optionsDownload as PowerPoint slide