Heteronuclear Dual Single-Atom Catalysts for Ambient Conversion of CO2 from Air to Formate

Single-atom catalysts (SACs) can achieve the maximum metal atom utilization, which exhibit great potential for the chemical transformation of CO 2 . However, an isolated single active site is less satisfactory for catalyzing multiple molecule reactions involving CO 2 hydrogenation. In this work, we propose heteronuclear dual SACs composed of Pd and 3d transition metals supported by covalent triazine frameworks (CTFs). Among these catalysts, the optimized Pd 1 –Co 1 /CTF catalyst exhibits up to 84.6% conversion of the captured CO 2 from air into formate at 30 °C and 1 bar. The in situ DRIFT characterization and density functional theory calculations reveal that CO 2 in air is captured by the Et 3 N solution as bicarbonate, which is then hydrogenated into formate via the Pd 1 –Co 1 heteronuclear dual single atom with an energy barrier as low as 17.2 kcal/mol. The heteronuclear Pd and Co metal atoms act as the active site for H 2 activation and CO 2 adsorption, respectively, thus exhibiting enhanced activity for formate synthesis with a synergistic effect. These findings present an insight into the synthesis and application of heteronuclear dual SACs and pave an avenue for conversion of CO 2 in the air by heterogeneous catalysts.