(中南大學(xué) 化學(xué)化工學(xué)院，長沙 410083)
摘 要: 以乙酸鈷(鋅)、苯并咪唑?yàn)樵希捎靡合喾焖俚睾铣山饘俜惺溥蝓ス羌?M-ZIFs)材料，通過高溫裂解，得到含氮碳材料M-Nx/C，并對其氧還原性能進(jìn)行研究。通過X射線衍射(XRD)，掃描電鏡(SEM)，透射電鏡(TEM)，X射線光電子能譜分析(XPS)和電化學(xué)測試等手段對合成催化劑的形貌、成分和電催化性能進(jìn)行了表征。通過比較發(fā)現(xiàn)，具有較高的石墨化程度和Co-Nx活性位點(diǎn)的Co-Nx/C材料的催化氧還原性能遠(yuǎn)高于Zn-Nx/C的，具有較正的氧還原起始電位(0.92 V)和半波電位(0.83 V)，接近鉑碳的指標(biāo)；而在穩(wěn)定性方面，該材料在反應(yīng)10000s后仍能保持94.2%的電流密度，遠(yuǎn)高于鉑碳的80.8%。
關(guān)鍵字: 含氮碳材料；氧還原；活性位點(diǎn)；電催化
（School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China）
Abstract:M-Nx/C was obtained by pyrolyzing the M-ZIFs through quick liquid phase reaction of cobalt (zinc) acetate and organic ligand (Benzimidazole). Then the morphology, composition and electrocatalytic activity were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectra (XPS) and electrochemical measurements. Compared with Zn-Nx/C, Co-Nx/C has higher eletrocatalytic activity for possessing high graphitization and CoNx active sites for oxygen reduction reaction (ORR). The onset potential and half wave potential of oxygen reduction on Co-Nx/C electrode are 0.92 V and 0.83 V, respectively, which are close to those of Pt/C. As for the stability, the Co-N/C maintains 94.2% current density after 10000 s, while the Pt/C maintains 80.8%.
Key words: N-containing carbon material; oxygen reduction; active site; eletrocatalysis
