In-situ fabrication of bio-inspired nanocatalysts for enhanced oxygen reduction reaction in alkaline media

Abstract

Designing a fuel cell based on non-precious metal-based electrocatalysts with high reduction potential and stability against methanol/carbon monoxide (MeOH/CO) poisoning is quite challenging. Taking inspiration from naturally occurring enzymes, materials with earth-abundant metal centers embedded in organic framework helps to expedite the kinetics of the oxygen reduction reaction (ORR) by providing more O2 adsorption sites through positively charged N atoms. Thus, herein, we have fabricated novel bioinspired nitrodopamine derived (NDA) N rich C coated bimetallic zeolitic imidazolate framework (NDA@BM-ZIF) through in-situ solvothermal synthesis approach. NDA@BM-ZIF based electrode offers high half wave potential value (E1/2 = 0.915 V) and high tolerance against MeOH poisoning (91.4%) even better than dopamine (DA) derived NC coated BM-ZIF (86.1%) and commercially available Pt/C (87.3%). The remarkable electrocatalytic efficacy of NDA@BM-ZIF could be ascribed to surface compatibility by providing positively charged O2 adsorption sites, increased surface defects and promote heterolytic O–O bond cleavage rather than homolytic cleavage thus resulting in fast electron transportation capability.