Designing highly efficient dual-metal single-atom electrocatalysts for the oxygen reduction reaction inspired by biological enzyme systems. Issue 27 (21st June 2018)

• Record Type: Journal Article
• Authors: Gong, Shipeng; Wang, Changlai; Jiang, Peng; Hu, Lin; Lei, Hu; Chen, Qianwang
• Is Part Of: Journal of materials chemistry. Volume 6:Issue 27(2018)
• Page Start: 13254
• Page End: 13262
• Publication Date: 2018-06-21
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c8ta04564j
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : Designing an efficient dual-metal catalyst Fe, Mn–N/C for the ORR, inspired by bio-enzymes. Abstract : Biological heme–copper oxidases (HCOs) play a critical role in the four-electron, four-proton reduction of O2 to H2 O in biosystems. HCOs exhibit high enzymatic activity due to their natural structure with heme–non-heme metal active sites, and the non-heme metal plays a role in conferring and fine-tuning the O2 reduction activity of the HCOs. Inspired by this binuclear active enzyme, herein, we designed an efficient electrocatalyst (Fe, Mn–N/C) for the oxygen reduction reaction, which contains two types of metal–N x active site incorporated within the graphene framework of porous carbon. The catalyst displayed remarkable ORR performance with a half-potential of 0.904 V and kinetic current density of 33.33 mA cm −2, which is 4.9 times that of 20% Pt/C (6.76 mA cm −2 ). When the Fe, Mn–N/C catalyst was applied as an air electrode in a Zn–air battery, it exhibited a superior performance compared to commercial Pt/C. Its discharge curve showed that the change in output voltage was negligible at 20 mA cm −2 for 23 000 seconds (6.4 h). First principles calculations revealed that Fe, Mn–N/C needs less energy for the protonation of O* to OH* in ORR procedures compared with Fe–N/C. This catalyst, with its bimetal reactive center mimicking a metal enzyme, will pave a new way to design efficient electrocatalysts for the ORR in fuel cells.