Porphyrin-Based Covalent Organic Framework Encapsulating Multiwalled Carbon Nanotubes: A High-Performance Electrocatalyst for Oxygen Reduction Reaction.

The development of efficient and cost-effective oxygen reduction reaction (ORR) catalysts is crucial for advancing fuel cell technologies, given the limitations of platinum-based catalysts. Here, we present a novel nanocomposite, cobalt-based porphyrinic covalent organic framework wrapped on multiwalled carbon nanotubes (Co-pCOF@MWCNTs), synthesized via template-directed in situ polymerization. This composite combines the high porosity and tunable catalytic properties of porphyrinic COFs with the excellent electrical conductivity of MWCNTs. The Co-pCOF@MWCNT demonstrates superior ORR activity, exhibiting an onset potential (Eonset) of 0.86 V vs RHE in 0.1 M KOH, surpassing the performance of its individual components (Co-pCOF and MWCNT) and other related materials. The enhanced catalytic efficiency is attributed to the synergistic interactions between the conductive MWCNT scaffold and the active porphyrinic COF nanolayers, which facilitate efficient charge transfer and increase catalytic site exposure. Furthermore, the nanocomposite exhibits high stability and methanol tolerance, establishing its potential as a cathodic material for fuel cells. This work highlights the promise of integrating COFs with conductive carbon materials and opens new avenues for the design of advanced ORR catalysts for energy conversion applications.