Catalytic Synthesis of Formamides by Integrating CO₂ Capture and Morpholine Formylation on Supported Iridium Catalyst

Herein we report an efficient and recyclable catalytic system for tandem CO₂ capture and N-formylation to value-added chemicals. CO₂ is apt to be captured by morpholine solution, while a highly efficient heterogeneous catalyst, isolated iridium atoms supported over nanadiamond/graphene, is discovered to be highly reactive for the formylation of morpholine, leading to the formation of N-formylmorpholine with excellent productivity (with a turnover number of 5 120 000 in a single batch reaction) and selectivity (>99 %). In addition, the CO₂ captured by morpholine under atmospheric conditions can be converted to N-formylmorpholine with decent conversion (51 %), which realizes the integration of CO₂ capture and conversion to value-added chemicals.