Catalysts with single metal atoms for the hydrogen production from formic acid

ABSTRACT Formic acid is a liquid organic hydrogen carrier. Metal and metal-complex catalysts are known to catalyze the hydrogen production from formic acid and hydrogen transfer reactions with formic acid as a hydrogen donor. In this review, we will show that heterogeneous catalysts with single metal atoms are promising for these reactions. The main emphasis is done to the catalysts with single atoms stabilized by pyridinic nitrogen atoms on the edge or vacancy sites of graphene sheets. The activity of the catalysts containing these sites often exceeds that of the catalysts with nanoparticles. We consider application of different physical methods and density functional theory calculations to establish the nature of single-atom active sites and reaction mechanism. Coordination of these sites significantly affects their performance in the mentioned reactions. This review could be useful for development of novel efficient catalysts.