Schiff Base-Mediated Dual Active Site Catalyst for Efficient N‑Formylation of Amines with CO2

Using CO2 as the C1 source for N-formylation of amine is a crucial energy-storage pathway to address the greenhouse effect while generating high-value-added chemicals but is limited by the activation of inert molecules. Herein, a dual active site catalyst with high CO2 activation and dihydrogen dissociation capacity was fabricated by incorporating a Schiff base and Au nanoparticles (NPs) on silicon dioxide (SiO2). The modification of the Schiff base not only provides an alkaline environment for CO2 absorption but also stabilizes Au NPs in a small and highly dispersed state, which regulates the electronic density of the metal for excellent H2 cleavage. The Schiff base-mediated Au catalyst significantly increased the yield of N-formylmorpholine from 3.9% in unmodified Au/SiO2 to 83.3% without the addition of any other additives. This work provides a new avenue for designing multisite catalysts by supporting surface modification to achieve simultaneous activation of multiple target substrates for synergistic catalysis.