Metal-Organic Framework-Supported Molecular Electrocatalysis for the Oxygen Reduction Reaction.

We report herein metal-organic framework (MOF)-supported Co porphyrins for the oxygen reduction reaction (ORR) with improved activity and selectivity. Co porphyrins can be grafted on MOF surfaces through ligand exchange. A variety of porphyrin@MOF hybrids were made using this method. Grafted Co porphyrins showed boosted ORR activity with large (> 70 mV) anodic shift of the half-wave potential compared to ungrafted porphyrins. By using active MOFs for peroxide reduction, the number of electrons transferred per O 2  increased from 2.65 to 3.70, showing significantly improved selectivity for the 4e ORR. We demonstrated that H 2 O 2  generated from O 2  reduction at Co porphyrins is further reduced at MOF surfaces, leading to improved 4e ORR. As a practical demonstration, these hybrids were used as air electrode catalysts in Zn-air batteries, which exhibited equal performance to that with Pt-based materials.
PMID: 33484092 [PubMed - as supplied by publisher]

Source: Angewandte Chemie - January 22, 2021 Category: Chemistry Authors: Liang Z, Guo H, Zhou G, Guo K, Wang B, Lei H, Zhang W, Zheng H, Apfel UP, Cao R Tags: Angew Chem Int Ed Engl Source Type: research