Hydrogen production through glycerol steam reforming over beehive-biomimetic graphene-encapsulated nickel catalysts. (January 2020)

• Record Type: Journal Article
• Authors: Chen, Dong; Wang, Wenju; Liu, Chenlong
• Is Part Of: Renewable energy. Volume 145(2020)
• Page Start: 2647
• Page End: 2657
• Publication Date: 2020-01
• Subjects: Glycerol steam reforming (GSR) -- Graphene -- Nickel -- SiO2 skeleton -- Rice husk char (RHC); Renewable energy sources -- Periodicals; Power resources -- Periodicals; Énergies renouvelables -- Périodiques; Ressources énergétiques -- Périodiques; 333.794
• DOI: 10.1016/j.renene.2019.08.022
• Languages: English
• ISSNs: 0960-1481

Abstract

Abstract: Graphene-encapsulated nickel catalysts were synthesized and attached to SiO2 skeleton, vividly described as "beehive-biomimetic catalysts". Rice husk char (RHC) served as the carbonaceous source in the synthesis. Different catalysts with nickel embedded inside graphene were tested in glycerol steam reforming (GSR) at 550, 600 and 650 °C. Catalysts were characterized by X-ray powder diffraction (XRD), Raman spectroscopy (Raman), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA). The effects of pretreating RHC or reaction temperature on yield of H2, selectivity of gaseous products, and molar ratios of H2 /CO and CO/CO2 were investigated. The catalyst with acid-treated RHC as the carbon precursor exhibited better catalytic activity and durability in GSR. It delivered a higher H2 yield of 5.09 mol H2 /mol glycerol and a higher H2 /CO ratio of 6.79 at 600 °C. The multilayered graphene prevented the oxidation, sintering, or acid corrosion of inner nickel without sacrificing its activity. The SiO2 skeleton also enhanced thermal stability of the catalyst. Highlights: A novel synthetic strategy to encapsulate Ni in multilayered graphene is preposed. Using RHC as catalyst precursor in GSR raises the value of glycerol and rice husk. The graphene shell protects the inner Ni from oxidation, sintering or acid corrosion. The catalyst produced by acid-treated RHC shows optimized H2 yield of 5.09 at 600 °C.