کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
44789 | 46353 | 2016 | 14 صفحه PDF | دانلود رایگان |
• Nano NixMgyO solid solution for hydrogen production via steam reforming was synthesised using three different methods.
• The carbon species deposited on different catalysts were characterised.
• NixMgyO solid solutions promoted CO2 adsorption and led to significantly enhanced anti-carbon deposition property.
• Hydrothermally prepared NixMgyO solid solution showed excellent durability and a high conversion of 97.4% after 20 h testing.
In this study, different types of nano NixMgyO solid solutions for the steam reforming of methanol were prepared via three different preparation methods. The solid solutions were characterised systematically by using a suite of characterisation techniques. TEM analysis demonstrated that Ni particles in these solid solutions were in nano-scale with an average size of 9.6–12 nm. The catalytic performance of these catalysts was evaluated using a fixed-bed reactor operated under atmospheric pressure at four different temperatures, i.e., 400, 500, 600 and 700 °C, and at two steam-to-carbon ratios (S/C), i.e., S/C = 1 and 3. Results showed that the nano NixMgyO material (NixMgyO-hydro), which was prepared using a hydrothermal method, achieved the highest methanol conversion efficiency of 97.4% and hydrogen yield of 58.5% under a S/C ratio of 3. The evaluation on carbon deposition resistance showed that nano NixMgyO-hydro had no detectable carbon deposited under a S/C ratio of 3. In addition, physical and chemical properties of these catalysts were also studied by using H2-Temperature-Programmed Reduction/Desorption(H2-TPR/D), CO2-Temperature- Programmed Desorption(CO2-TPD) and X-ray Photoelectron Spectroscopy(XPS). The outstanding carbon deposition resistance of NixMgyO-hydro was attributed to the “isolation effect” of the NixMgyO solid solution structure, which restricts Ni nano particles from aggregation. The high basicity of the surface of NixMgyO-hydro catalyst also resulted in the enhanced adsorption of CO2 and therefore contributed to anti-carbon deposition by providing oxygen to promote the gasification reaction between carbon and CO2.
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Journal: Applied Catalysis B: Environmental - Volume 194, 5 October 2016, Pages 84–97