CVD grown graphene as catalyst for acid electrolytes. (7th June 2018)

• Record Type: Journal Article
• Authors: Yazici, M. Suha; Azder, M. Akif; Salihoglu, Omer
• Is Part Of: International journal of hydrogen energy. Volume 43:Number 23(2018)
• Page Start: 10710
• Page End: 10716
• Publication Date: 2018-06-07
• Subjects: CVD -- Porous graphene -- N-doping -- Oxygen reduction -- RDE; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2018.01.180
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Chemical Vapor Deposition (CVD) process is utilized to grow and study behavior of porous, continuous-phase 3D graphene structures in acid electrolyte. Graphene layers that are produced by CVD process are tested for oxygen reduction reaction (ORR) activity by Rotating Disc Electrode (RDE) measurements in 0, 1 M HClO4 electrolyte. Raman spectroscopy measurements confirms multi-layer porous structure formation for more than 1 min grow on nickel foam. Multi-layer porous graphene has provided μA level current. When NH3 is used for nitrogen (N)-doping, magnitude of the reduction current increases, but still low for practical usage of graphene in acid electrolytes as catalyst. N-doping is confirmed with XPS measurements showing all possible types of N-doping phases with 900 °C being better than 1000 °C doping. CVD grown continuous-phase graphene, by itself or N-doped, cannot provide enough electrocatalytic activity to be used in 0, 1 M HClO4 acid electrolyte or polymer electrolyte membrane (PEM) fuel cells for practical applications. Pt layer of 10 nm has been sputtered on to graphene (21.45 μg/cm 2 Pt loading) and has provided orders of magnitude increase in oxygen reduction current compare to bare graphene layers. Highlights: CVD grown graphene may be a good candidate as catalyst support for acid electrolytes and PEM fuel cells. XPS confirms different forms of nitrogen doping by NH3 on graphene samples. Sputtering of catalyst on CVD graphene can be utilized for continuous production of electrodes. 10 nm coating of Pt on CVD graphene shows oxygen activity in HClO4 electrolyte.