CO₂ Hydrogenation Catalysts with Deprotonated Picolinamide Ligands

Abstract

In an effort to design concepts for highly active catalysts for the hydrogenation of CO<sub>2</sub> to formate in basic water, we have prepared in this paper several catalysts with picolinic acid, picolinamide, and its derivatives, and we investigated their catalytic activity. The CO<sub>2</sub> hydrogenation catalyst having a 4-hydroxy-N-methylpicolinamidate ligand exhibited excellent activity even under ambient conditions (0.1 MPa, 25 °C) in basic water, exhibiting a TON of 14700, a TOF of 167 h<sup>–1</sup>, and producing a 0.64 M formate concentration. Finally, its high catalytic activity originates from strong electron donation by the anionic amide moiety in addition to the phenolic O<sup>–</sup> functionality.