Sorption-enhanced hydrogen production by steam reforming of ethanol over mesoporous Co/CaOAl2O3 xerogel catalysts: Effect of Ca/Al molar ratio. (2nd March 2017)

• Record Type: Journal Article
• Authors: Han, Seung Ju; Song, Ji Hwan; Yoo, Jaekyeong; Park, Seungwon; Kang, Ki Hyuk; Song, In Kyu
• Is Part Of: International journal of hydrogen energy. Volume 42:Number 9(2017)
• Page Start: 5886
• Page End: 5898
• Publication Date: 2017-03-02
• Subjects: Hydrogen production -- Steam reforming of ethanol -- Multifunctional Co/CaO–Al2O3 xerogel catalyst -- Cobalt catalyst -- Sorption-enhanced hydrogen production; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2016.12.075
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: A series of multifunctional Co/CaOAl2 O3 catalysts (Co/XCA, X = 0, 0.25, 0.5, 0.75, and 1.0) with different Ca/Al molar ratio (X) were prepared for use in the sorption-enhanced hydrogen production by steam reforming of ethanol. Mesoporous structure was successfully formed in all the calcined catalysts, and surface area of the catalysts decreased with increasing Ca/Al molar ratio. Co3 O4, CaCO3, and γ-Al2 O3 phases were dominantly formed in the calcined catalysts. It was revealed that addition of Ca neutralized support acidity, resulting in a decrease of C2 H4 selectivity. Addition of Ca also increased strong base sites which were related to sorption-enhanced hydrogen production at the initial reaction stage. In the XRD and H2 -TPD analyses, Co/0.5CA catalyst retained the smallest crystallite size of metallic cobalt and the highest cobalt surface area among the catalysts. Catalytic activity in the steam reforming of ethanol exhibited a volcano-shaped trend with respect to Ca/Al molar ratio. Hydrogen yield increased with increasing cobalt surface area. Among the catalysts tested, Co/0.5CA catalyst with the highest cobalt surface area showed the best catalytic performance. Thus, cobalt surface area served as a crucial factor determining the catalytic activity for ethanol steam reforming. Low acidity and high surface area were also responsible for stable catalytic activity of Co/0.5CA catalyst in the steam reforming of ethanol. Graphical abstract: Highlights: Sorption-enhanced hydrogen production by ethanol steam reforming was conducted. Co/CaOAl2 O3 catalysts (Co/XCA) with different Ca/Al molar ratio (X) were prepared. Hydrogen yield increased with increasing cobalt surface area of the catalysts. Co/XCA (X = 0.25, 0.5, and 0.75) catalysts showed a sorption-enhancement effect.