Effect of carbon precursor and initial pH on cobalt-doped carbon xerogel for oxygen reduction. (14th June 2018)

• Record Type: Journal Article
• Authors: Zainul Abidin, Azim Fitri; Loh, Kee Shyuan; Wong, Wai Yin; Mohamad, Abu Bakar; Puspasari, Ifa
• Is Part Of: International journal of hydrogen energy. Volume 43:Number 24(2018)
• Page Start: 11047
• Page End: 11055
• Publication Date: 2018-06-14
• Subjects: Carbon xerogel -- Cobalt doping -- Oxygen reduction reaction -- Catalyst; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2018.05.015
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: In this study, cobalt-doped carbon xerogel (Co-CX) was synthesised via sol-gel polymerisation of phenolic compounds (i.e., resorcinol, phenol and m-cresol) and formaldehyde, and this polymerisation was catalysed by cobalt nitrate and followed by a carbonisation process. The effect of the initial pH value (5.5, 6.5 and 7.5) as well as the type of carbon precursors on the structural properties of Co-CX was investigated via field emission scanning electron microscope (FESEM), Brunauer-Emmett-Teller (BET) and X-ray diffractometry (XRD). The catalytic activity of Co-CX for the oxygen reduction reaction (ORR) in 0.1 M KOH was studied using a rotating ring-disk electrode (RRDE) technique. The structural properties and ORR activities were affected by different initial pH values as well as the type of carbon precursor. A carbon precursor consisting of resorcinol-formaldehyde with an initial pH value of 7.5 exhibited the best catalytic activity. The initial pH plays an important role in promoting micro/mesopores. The FESEM and BET results revealed that Co doping promotes the formation of additional pores. The RRDE result indicated that Co-CX exhibited good catalytic activity that tends to favour a four-electron pathway. Graphical abstract: Image 1 Highlights: Facile synthesis of a Co-CX catalyst via a simple sol-gel method is presented. Effect of carbon precursors and pH on as-synthesised Co-CX are discussed. Catalytic activities of Co-CX are correlated to its microstructure.