Background: The generation of hydrogen by electrochemical reduction of water, represents
an attractive approach for storing the electrical energy transiently produced by renewable energy
sources, and catalysts based on transition metal compounds are used to increase the reaction rate.
Despite much progress in water reduction catalysis, structural complexity, insolubility in aqueous media
and low pH conditions severely limit their practical utility. To meet this goal, we design an
electrocatalyst based on Co(TCNQ)2 (TCNQ: 7,7,8,8-tetracyanoquinodimethane). This compound is
water soluble and can catalyze proton or water reduction.
Methods: The reaction of LiTCNQ with CoCl2.6H2O yields a cobalt-TCNQ compound, Co(TCNQ)2 1.
This compound has been characterized by spectroscopic, physics-chemical and electro-chemical
Results: Electrochemical studies show that the electrocatalytic system formed by compound 1 achieves
a turnover frequency (TOF) of 767 moles h-1 H2 from a neutral buffer solution (pH 7.0) at an
overpotential (OP) of 0.638 V.
Conlusions: The result suggests that the addition of TCNQ is the key feature for highly catalytic
activity of 1. This can be attributed to the introduction of TCNQ- ion to cobalt center, stabilizing the low
oxidation state of cobalt.