The study of the performance of Ni-based catalysts obtained from LaNiO3 perovskite-type oxides synthesized by the combustion method for the production of hydrogen by reforming of ethanol
•LaNiO3 perovskite-type oxides were prepared by the self combustion method.•Fuel-to-oxidizers ratio (φ) and reaction conditions affected activity and stability.•Carbon was formed during steam reforming of ethanol at 773 K for all catalysts.•Decreasing φ reduced the amount of carbon formed due to smaller Ni crystallite size.•The addition of water or oxygen to the feed inhibits carbon formation at 1073 K.
The performance of Ni-based catalysts synthesized by the combustion method, using different fuel-to-oxidizers ratios (φ), for ethanol conversion reactions was investigated. All catalysts were selective to hydrogen for steam reforming (SR) of ethanol. Regardless of the φ value, all catalysts deactivated during SR of ethanol at 773 K. Scanning electron microscopy and thermogravimetric analyses showed that the loss of activity was due to carbon deposition. However, decreasing φ reduced the amount of carbon formed. This was related to the smaller crystallite size of metallic Ni obtained for the sample with lower φ, as revealed by X-ray diffraction experiments. On the other hand, the catalysts were very stable at high reaction temperature (1073 K). The occurrence of the reverse of Boudouard reaction and the carbon gasification reaction inhibited carbon deposition. Furthermore, the presence of water or oxygen in the feed promoted the mechanism of carbon removal and catalyst stability.
Graphical abstractLaNiO3-0.7 after SR of ethanol at 1073 K is quite stable and did not exhibit carbon formation.Figure optionsDownload full-size imageDownload high-quality image (218 K)Download as PowerPoint slide
Journal: Catalysis Today - Volume 213, 15 September 2013, Pages 25–32