Conjugated Covalent Organic Frameworks as Platinum Nanoparticle Supports for Catalyzing the Oxygen Reduction Reaction

摘要

Developing highly efficient and durable electrocatalysts for the oxygen reduction reaction (ORR) is essential for commercializing renewable and clean energy, but this remains a challenge. Herein, we design an electrocatalyst by confining Pt nanoparticles on a conjugated nitrogen-rich covalent organic framework (COF) and demonstrate its ORR activity in an acid electrolyte. In the catalyst, multiple pyridinic nitrogens act as nucleation sites for controllably growing Pt in a layer over the COF’s surface and the pore channel, resulting in uniform Pt distribution and more accessible Pt active sites. The catalyst exhibits ultrahigh ORR activity with an onset potential of 1.05 V versus reversible hydrogen electrode and a half-wave potential of 0.89 V, which are more positive than those of commercial Pt/C and other reported catalysts. This strategy offers a new way to fabricate electrocatalysts with atomically definite active sites and high-performance catalytic activities for clean energy storage and conversion.