A class of transition metal-oxide@MnOx core–shell structured oxygen electrocatalysts for reversible O2 reduction and evolution reactions. Issue 36 (29th August 2016)

• Record Type: Journal Article
• Authors: Cheng, Yi; Dou, Shuo; Saunders, Martin; Zhang, Jin; Pan, Jian; Wang, Shuangyin; Jiang, San Ping
• Is Part Of: Journal of materials chemistry. Volume 4:Issue 36(2016)
• Page Start: 13881
• Page End: 13889
• Publication Date: 2016-08-29
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c6ta04758k
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : A novel metal-oxide@MnO x core–shell type structured electrocatalyst has been developed with an excellent bifunctional activity for the ORR and OER and good durability. Abstract : It is highly desirable but challenging to develop a highly active as well as durable bifunctional electrocatalyst for the reversible oxygen reduction reaction and evolution reaction (ORR & OER). Here a new class of bifunctional oxygen electrocatalysts has been developed based on ultrafine transition metal-oxide nanoparticles (NPs), such as NiO, FeO or NiFeO, embedded in an amorphous MnO x shell, where the embedded NP core contributes to the high OER activity and the porous amorphous MnO x shell functions as an effective ORR catalyst as well as providing effective structural confinement to the metal-oxide NP core. The best performance was obtained for NiFeO@MnO x, exhibiting a potential gap, Δ E, of 0.798 V to achieve a current of 3 mA cm −2 for the ORR and 5 mA cm −2 for the OER in 0.1 M KOH solution, better than that of Ir/C (0.924 V) and Pt/C (1.031 V). Most importantly, NiFeO@MnO x shows superior stability due to the outstanding structural confinement effect of the amorphous MnO x, achieving a Δ E of 0.881 V after 300 cycles, outperforming 1.093 V obtained for the state-of-the-art Ir–Pt/C oxygen electrocatalysts.