Densely populated single-atom catalysts for boosting hydrogen generation from formic acid

The single-atom M-N-C (M typically being Co or Fe) is a prominent material with exceptional reactivity in areas of catalysis for sustainable energy. However, the formation of metal nanoparticles in M-N-C materials is coupled with high-temperature calcination conditions, limiting the density of M-N_x active sites and thus restricting the catalytic performance of such catalysts. Herein, we describe an effective decoupling strategy to construct high-density M-N_x active sites by generating polyfurfuryl alcohol in the MOF precursor, effectively preventing the formation of metal nanoparticles even with up to 6.377% cobalt loading. This catalyst showed a high H₂ production rate of 778 mL g_cat⁻¹ h⁻¹ when used in the dehydrogenation reaction of formic acid. In addition to the high density of the active site, a curved carbon surface in the structure is also thought to be the reason for the high performance of the catalyst.