Insights into the Mechanism of CO₂ Electroreduction by Molecular Palladium-Pyridinophane Complexes

Herein, we report the synthesis, characterization, and electrocatalytic CO₂ reduction activity of a series of Pd(II) complexes supported by tetradentate pyridinophane ligands. In particular, we focus on the electrocatalytic CO₂ reduction activity of a Pd(II) complex supported by the mixed hard--soft donor ligand 2,11-dithia[3.3](2,6)pyridinophane (N2S2). We also provide spectroscopic evidence of a CO-induced decomposition pathway for the same catalyst, which provides insights into catalyst poisoning for molecular Pd CO₂ reduction electrocatalysts.