通过惰性气氛下高温热解沸石咪唑酯框架(ZIF-8)纳米颗粒得到氮掺杂多孔碳(NPC),再将其与植酸和铁源进行浸渍后,在氩氨混合气中进行二次煅烧,获得磷共掺杂改性的多孔铁氮碳氧还原电催化剂(Fe/PN/C)。考察了分步煅烧温度、煅烧气氛、植酸添加量等制备条件对其组成、结构及氧还原电催化性能的影响,并利用XRD、XPS、TEM、BET等对催化剂组成和结构进行表征。结果表明,性能最优的多孔氮磷共掺杂Fe/PN/C催化剂具有高达1 014.3 m²/g的比表面积,吡啶氮和石墨氮物种占比高。电化学性能测试结果表明,最优的Fe/PN/C电催化剂的半波电位为0.902 V,较商用贵金属铂催化剂高约22 mV,而未掺杂磷元素的对照样品Fe/N/C-900-900的半波电位为0.885 V,表明磷元素共掺杂可提高铁氮碳材料在碱性条件下对氧还原的电催化性能。

To develop efficient electrocatalysts for oxygen reduction reaction (ORR),nitrogen-doped porous carbon (NPC) is firstly obtained through pyrolysis of zeolite imidazate framework (ZIF-8) nanoparticles in an inert atmosphere,and then immersed with phytic acid and iron source,and finally calcined in the mixture of Ar and ammonia,resulting in a porous iron-nitrogen-carbon co-doped with phosphorus (Fe/PN/C).The effects of calcination temperature in such a stepwise process,calcination atmosphere,and the dosage of phytic acid on the compositional and structural features as well as the electrochemical performance of the resulting Fe/PN/C materials are investigated.The electrocatalysts are characterized with XRD,XPS,TEM,BET etc.The best Fe/NP/C features a specific surface area as large as 1,014.3 m²·g^-1,and a high proportion of pyridine nitrogen and graphitic nitrogen species.According to electrochemical measurements,the best Fe/NP/C displays a half-wave potential (E_1/2) as high as 0.902 V for alkaline ORR electrocatalysis,22 mV higher than that of commercial Pt/C,while the control sample without phosphorus co-doping yields a E_1/2 of 0.885 V.Such a result proves the positive role of phosphorus co-doping in enhancing the catalytic activity of Fe-N-C materials.

王源(1998-),女,硕士研究生,研究方向为电催化,15162117960@163.com。