Pd-Imidate@Sba-15: A Multifunctional Heterogeneous Catalyst for the Aqueous Room Temperature Hydrogenation of Co2 to Formic Acid

Abstract

The incorporation of hydrophilic and basic sites from phosphotriazaadamantane and saccharine in a water-soluble Pd complex and the subsequent confinement into mesoporous silica support increases the activity and stability of the palladium catalytic species for the room-temperature aqueous hydrogenation of either bicarbonate or CO₂ into formic acid. The use of low Pd loadings (<0.1 mmol_Pd g^-1) of the well-dispersed complex on SBA-15 mesoporous silica allows performing the reaction under room temperature, and aqueous conditions, exhibiting TON of ca. 40-100, for the CO₂ or bicarbonate hydrogenation, respectively, which is one order of magnitude higher than the homogeneous case, allowing the easy isolation and recycling of the solid catalyst.

Keywords: CO2activation; Formic acid; Heterogeneous catalysis; Mesoporous silica.