A copper-modified covalent triazine framework (Cu-CTF) catalyzed the selective electrochemical reduction of nitrobenzene to aniline in neutral aqueous solutions with a faradaic efficiency reaching up to 65% at -0.6V versus Ag/AgCl. Electrochemical characterization indicated that the organic-framework part of Cu-CTF reduced nitrobenzene to phenylhydroxylamine, followed by the reduction of phenylhydroxylamine to aniline at single Cu sites. This is the first example of a cooperative electrocatalytic reaction at metal centers and at the framework with a metal-modified CTF.