Engineering the Microstructure at Co Single-Atom Sites by Co Nanoparticles Core for Enhanced Formic Acid Selective Dehydrogenation

Abstract

The liquid hydrogen storage material, formic acid, is a promising solution to utilize hydrogen energy safely and efficiently. However, a low-cost and efficient catalyst for formic acid dehydrogenation is needed to build such a formic acid-based hydrogen storage system. Based on cheap non-noble metal, we constructed a cobalt catalyst with hybrid core−shell structural active sites, which significantly promote formic acid selective dehydrogenation from 200 to 1619 mL g −1 h −1 and suppress the carbon monoxide formation from 1644 to 92 ppm. Such a hybrid core−shell structure consists of single atomic Co sites anchored carbon layers shell and Co nanoparticle core. The hybrid structure has excellent antiacid leaching stability to catalyze neat formic acid decomposition. The density functional theory calculations reveal that the changes in microstructure at single atomic Co sites optimize the adsorption energy of the intermediate, resulting in a lower dehydrogenation energy barrier and a higher dehydration energy barrier.