In the reaction of catalytic oxidation of CH4,CO2 with O2 to synthesis gas, carbon-deposition is an important factor for deactivation. By adding different oxides to Ni/AI2O3 catalyst, its resistance to carbon-depositi...In the reaction of catalytic oxidation of CH4,CO2 with O2 to synthesis gas, carbon-deposition is an important factor for deactivation. By adding different oxides to Ni/AI2O3 catalyst, its resistance to carbon-deposition was improved. The experimental results indicate that the order of resistance to carbon-deposition is as follows: Ni/CaO-AI2O3>Ni/MgO-AI2O3>Ni/ TiO2-AI2O3>Ni/CeO2-AI2O3>Ni/La2O3-AI2O3>Ni/Y2O3-AI2O3>Ni/Fe2O3-AI2O3>Ni/AI2O3. The catalysts were characterized by CO2-TPD, O2-TPD and XPS methods. Here the relation between the order of resistance to carbon-deposition and performance of catalyst is discussed.展开更多
现代工业制氢技术中,甲烷重整制氢具有反应物丰富、可利用性高等独特优势,尤其甲烷干重整(Dry Reforming of Methane,DRM)技术,以甲烷和二氧化碳为原料,兼具环境和经济效益,而催化剂积碳是影响DRM技术发展的主要问题之一.从催化剂活性...现代工业制氢技术中,甲烷重整制氢具有反应物丰富、可利用性高等独特优势,尤其甲烷干重整(Dry Reforming of Methane,DRM)技术,以甲烷和二氧化碳为原料,兼具环境和经济效益,而催化剂积碳是影响DRM技术发展的主要问题之一.从催化剂活性组分、载体和助剂方面,详细阐述催化剂组分相互作用、活性金属粒径、碱度、储氧能力和积碳类型对DRM催化剂抗积碳性能的影响.分析发现活性金属和载体的强相互作用、双金属的协同作用以及较小的活性金属颗粒均有助于减少积碳和提高催化剂活性,提高催化剂的储氧能力能促进碳脱除,积碳类型及数量与载体密切相关,载体碱度适中有助于增强CO_(2)的活化,提高催化剂抗积碳能力.研究结果为甲烷干重整制氢催化剂的设计和优化提供参考.展开更多
Cathodic arc evaporation is a well-established physical vapor deposition technique which is characterized by a high degree of ionization and high deposition rate. So far, this technique has been mainly used for the de...Cathodic arc evaporation is a well-established physical vapor deposition technique which is characterized by a high degree of ionization and high deposition rate. So far, this technique has been mainly used for the deposition of tribological coatings. In this study, anti-corrosive and electrical conductive carbon-based coatings with a metallic interlayer were prepared on stainless steel substrates as surface modification for metallic bipolar plates. Hereby, the influence of the deposition temperature during the deposition of the carbon top layer was investigated. Raman spectroscopy revealed differences in the microstructure at 200°C compared to 300°C and 100°C. Measurements of the interfacial contact resistance showed that the deposited coatings significantly improve the electrical conductivity. There are only minor differences between the different carbon top layers. The corrosion resistance of the coatings was studied via potentiodynamic polarization at room temperature and 80°C. Experiments showed that the coating with a carbon top layer deposited at 200°C, considerably reduces the current density and thus corrosion of the substrate is suppressed.展开更多
文摘In the reaction of catalytic oxidation of CH4,CO2 with O2 to synthesis gas, carbon-deposition is an important factor for deactivation. By adding different oxides to Ni/AI2O3 catalyst, its resistance to carbon-deposition was improved. The experimental results indicate that the order of resistance to carbon-deposition is as follows: Ni/CaO-AI2O3>Ni/MgO-AI2O3>Ni/ TiO2-AI2O3>Ni/CeO2-AI2O3>Ni/La2O3-AI2O3>Ni/Y2O3-AI2O3>Ni/Fe2O3-AI2O3>Ni/AI2O3. The catalysts were characterized by CO2-TPD, O2-TPD and XPS methods. Here the relation between the order of resistance to carbon-deposition and performance of catalyst is discussed.
文摘现代工业制氢技术中,甲烷重整制氢具有反应物丰富、可利用性高等独特优势,尤其甲烷干重整(Dry Reforming of Methane,DRM)技术,以甲烷和二氧化碳为原料,兼具环境和经济效益,而催化剂积碳是影响DRM技术发展的主要问题之一.从催化剂活性组分、载体和助剂方面,详细阐述催化剂组分相互作用、活性金属粒径、碱度、储氧能力和积碳类型对DRM催化剂抗积碳性能的影响.分析发现活性金属和载体的强相互作用、双金属的协同作用以及较小的活性金属颗粒均有助于减少积碳和提高催化剂活性,提高催化剂的储氧能力能促进碳脱除,积碳类型及数量与载体密切相关,载体碱度适中有助于增强CO_(2)的活化,提高催化剂抗积碳能力.研究结果为甲烷干重整制氢催化剂的设计和优化提供参考.
文摘Cathodic arc evaporation is a well-established physical vapor deposition technique which is characterized by a high degree of ionization and high deposition rate. So far, this technique has been mainly used for the deposition of tribological coatings. In this study, anti-corrosive and electrical conductive carbon-based coatings with a metallic interlayer were prepared on stainless steel substrates as surface modification for metallic bipolar plates. Hereby, the influence of the deposition temperature during the deposition of the carbon top layer was investigated. Raman spectroscopy revealed differences in the microstructure at 200°C compared to 300°C and 100°C. Measurements of the interfacial contact resistance showed that the deposited coatings significantly improve the electrical conductivity. There are only minor differences between the different carbon top layers. The corrosion resistance of the coatings was studied via potentiodynamic polarization at room temperature and 80°C. Experiments showed that the coating with a carbon top layer deposited at 200°C, considerably reduces the current density and thus corrosion of the substrate is suppressed.
