Atomic cobalt anchored on covalent triazine frameworks with ultra-high performance towards oxygen reduction reaction

Single cobalt atom is promising non-precious metal catalyst instead of Pt in the oxygen reduction reaction (ORR). However, it is still a great challenge to develop a cost-effective, ultrastable and efficent single-atom cobalt catalyst for ORR, requiring efficient fabrication strategies and robust support to stabilize the single cobalt atom. Here, we prepared a highly active and stable atomically isolated cobalt catalyst via covalent triazine framework (CTF) support with Ketjen Black (KB) hybridization in scale. The prepared single Co catalyst (Co-CTF/KB) possesses high metal loading over 4 wt% and shows superior ORR performance with a half-wave potential ( E 1/2) of 0.830 V and a limiting current density of 6.14 mA cm−2 as well as high tolerance of methanol in an alkaline medium, which outperforms commercial Pt/C and most non-precious-metal catalysts reported to date. Benefiting from strong stabilization of Co atoms on CTF, Co-CTF/KB shows outstanding stability with only 5 mV negative shifts after 10,000 cycles. Moreover, it also displays high catalytic activity for oxygen evolution reaction (OER), suggesting it is an efficient ORR/OER bifunctional catalyst. The present work provides a facile strategy for preparing single-atom catalysts in bulk quantity and contributes to development of catalysts for electrochemical conversion and storage devices.