Nickel-organic frameworks as highly efficient catalyst for electrochemical conversion of CH₃OH into formic acid

To improve the reaction rate and the yield of high value-added product (formic acid) of electrocatalytic methanol oxidation reaction (MOR), the development of high-performance electrocatalyst is essential. In this work, novel nickel-organic framework nanosheets comprising Ni²⁺ and an organic ligand of hexamethylenetetramine (Ni-MOFs-t, where t is the solvothermal temperature) are synthesized by a facile one-pot solvothermal method. By structural regulation of Ni-DMAP-t, the self-supported Ni-MOFs-120 nanosheets on Ni foam (Ni-MOFs-120/NF) exhibits high electrocatalytic activity toward MOR with a low potential of 1.44 V (vs RHE) at a current density of 100 mA cm⁻². Electrochemical measurement has also demonstrated that the Ni-MOFs-120/NF possesses superior stability for MOR. Particularly, the selectively conversion of methanol to formic acid was achieved under the catalysis of Ni-MOFs-120/NF. This work offers a new high-performance electrocatalytic material for the conversion of methanol to high value-added formic acid. © 2022 The Author. Published by Elsevier B.V.