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Metal-nitrogen-doped carbon for bifunctional electrochemical energy conversion and storage |
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| รหัสดีโอไอ | |
| Title | Metal-nitrogen-doped carbon for bifunctional electrochemical energy conversion and storage |
| Creator | Pirapath Arkasalerks |
| Contributor | Khanin Nueangnoraj, Advisor |
| Publisher | Thammasat University |
| Publication Year | 2568 |
| Keyword | CO2 reduction, Oxygen reduction, Oxygen evolution, Metal-air batteries, N-doped carbon, Metal-support interaction, การรีดักชันคาร์บอนไดออกไซด์, การรีดักชันออกซิเจน, การเกิดออกซิเจน, แบตเตอรี่โลหะ–อากาศ, คาร์บอนเจือไนโตรเจน, อันตรกิริยาระหว่างโลหะกับตัวรองรับ |
| Abstract | The development of efficient and stable electrocatalysts is essential for advancing electrochemical energy conversion and storage technologies. Among various strategies, coupling metals with conductive carbon supports has shown great promise in enhancing both activity and durability. Nitrogen-doped carbon (NC) has emerged as a particularly effective candidate due to its high electrical conductivity, tunable electronic structure, and abundance of defect sites that act as anchoring centers for metal species.This research began with a tea-leaf–derived N-doped carbon (TL9) supporting Cu2O nanoparticles for the CO2 reduction reaction (CO2RR) as the energy conversion. The defect-rich TL9 framework effectively stabilized Cu+ species and promoted faradaic efficiencies approaching 90% for CO and formate at −0.6 V vs RHE and maintains over 60% selectivity after 24 h of continuous operation, confirming the crucial role of nitrogen in mediating electron transfer and preventing over-reduction to metallic Cu0. Because the CO2 reduction and oxygen reduction reactions share similar interfacial electron-transfer pathways—both involving the activation of small molecules through multi-electron processes—insights from CO2RR can be directly translated to oxygen electrocatalysis. To translate these mechanistic principles into a energy storage configuration, the focus shifted toward oxygen electrocatalysis, where oxygen can be directly utilized as the reactant in Li–air batteries (LABs). Consequently, a bio-derived polymer, poly(2,5-pyridinediylbenzimidazole) (PYPBI), was employed as a precursor for an NC with an exceptionally high nitrogen content. This approach was driven by the earlier observation that nitrogen functionalities play a decisive role in stabilizing metals and facilitating charge transfer. By intentionally maximizing the nitrogen concentration, the PYPBI-derived carbon aimed to further enhance metal–support interactions and catalytic durability. The resulting CoFe2O4/PYPBI composite was therefore investigated as a bifunctional catalyst for the oxygen reduction and evolution reactions (ORR/OER) in LABs. The LAB demonstrated a high discharge capacity of 18,356 mAhg−1 at a current density of 200 mAg−1, maintaining a remarkable discharge capacity of 1,000 mAhg−1 even at a high current density of 400 mAg−1 for 200 cycles.While CO2RR provides a pathway for carbon utilization, the LAB system offers a more realistic configuration for energy storage, operating with ambient oxygen as the cathodic reactant. Therefore, this research bridges electrochemical conversion and energy storage within a unified framework, where NC acts as a structural and electronic stabilizer for metals across both reductive and oxidative environments. The comparative insights derived from these two systems advance the understanding of metal–support interactions, providing a rational design principle for next-generation electrocatalysts in sustainable energy technologies. |
