Ultrathin two-dimensional triptycence-based metal-organic framework for highly selective CO2 electroreduction to CO

Efficient CO₂ reduction reaction (CO₂RR) is one of the important topics in energy and environment field, but improving the electrochemical selectivity of specific product is a great challenge. Herein, we reported a unprecedented two-dimensional (2D) metal?organic framework with CuO₄ unit (denoted as Cu-HHTT, HHTT = 9,10-dihydro-9,10-1,2]benzenoanthracene-2,3,6,7,14,15-hexaol) as the electrocatalyst for CO₂RR. Cu-HHTT exhibits high performance for CO₂RR to produce CO, namely Faradaic efficiency of 96.6% toward CO with a current density of 18 mA/cm² at the potential of ?0.6 V vs. RHE. Density function theory reveals that the desorption of CO species exhibits a lower energy barrier than that of hydrogenation of *CO intermediate, resulting in CO as the main product instead of alcohols or hydrocarbons.