LAUSR

A pyrimidine-modified covalent organic framework (COF-Pyr) was designed to be synthesized via the Povarov reaction. The nitrogen atom on the pyrimidine showed excellent coordination ability to metal ions. Their stable metal composite material (Co@COF-Pyr) exhibited remarkable performance for electrocatalytic OER in 1.0 M KOH aqueous solution. The overpotential was 450 mV at 10 mA cm -2 . The Co@COF-Pyr with large specific surface area (392 m 2 g -1 ) and regular crystal structure provided free passage for H 2 O to move and make them fully contact with the uniformly dispersed cobalt ions in the surface. Thus, the turnover frequency (TOF) value of Co@COF-Pyr was 0.1 s -1 at the overpotential of 370 mV, which was higher than most reported OER catalysts. This work provided a new way to design and prepare nitrogen containing heterocyclic functionalized COFs. They can be combined with metal ions to expand the application of COFs in the field of electrocatalysis.