Coordination Polymers with 2,2':6',2″-Terpyridine Earth-Abundant Metal Complex Units for Selective CO₂ Photoreduction

Combining molecular metal complexes into coordination polymers (CPs) is an effective strategy for developing photocatalysts for CO₂ reduction; however, most such reported catalysts are noble metal-containing CPs. Herein, two novel Zr-containing bimetallic CPs, Co-Zr and Ni-Zr, were designed and successfully synthesized by connecting 2,2':6',2″-terpyridine-based molecular earth-abundant metal (Co or Ni) complexes with ZrO₈ nodes. Both CPs were applied as catalysts for CO₂ photoreduction to selectively produce CO. The catalytic performance of Co-Zr is better than that of Ni-Zr with a yield of 3654 μmol (g of catalyst)^-1 for CO in 6 h (TON = 18.2). The difference between these two catalysts was analyzed with respect to band structure and charge migration ability. This work provides an effective way to introduce molecular earth-abundant metal complexes into coordination polymers for the construction of efficient noble metal-free CO₂ photocatalysts.