Mechanism difference between nanoparticles and single-atom sites on aqueous formic acid dehydrogenation over coblat catalyst

Abstract

Various Co-N-C catalysts including nanoparticles and single-atom sites were prepared using a low-temperature synthetic strategy by vacuum calcining with high exposure of the active sites and low energy consumption. When used in the formic acid (FA) dehydrogenation reaction, the obtained single-atom sites catalyst displayed high catalytic activity with a high H2 production rate of 27,361 mL·g−1·h−1. Moreover, the single-atom sites catalysts can still exhibit astonished catalytic performance in 88% FA (cheapest commercially available grade of FA) due to their super stability and special mechanism of reaction. From TEM, XRD, HAADF-STEM, XPS, and XANES characterization, the atomically dispersed active sites in the single-atom sites catalysts caused by strong metal-nitrogen coordination is believed to be the key to the success of this reaction. Moreover, the mechanism difference between nanoparticles and single-atom sites on aqueous formic acid dehydrogenation over coblat catalyst was illustrated.