Kinetic isotope effect offers selectivity in CO2 reduction

Abstract

A binuclear Ni complex with N,O donors catalyzes CO₂ reduction via its Ni(I) state. The product distribution when H₂O is used as a proton source shows similar yields for CO, HCOOH and H₂. However, when D₂O is used, the product distribution shows a ∼65% selectivity for HCOOH. In situ FTIR indicates that the reaction involves a Ni–COO* and a Ni–CO intermediate. Differences in H/D KIEs on different protonation pathways determine the selectivity of CO₂ reduction.