镍负载量对Ni/MgO(111)催化甲烷二氧化碳重整反应性能影响
Effect of Ni loadings on the catalytic properties of Ni/MgO(111) catalyst for the reforming of methane with carbon dioxide
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摘要: 研究了MgO(111)负载镍基催化剂催化甲烷二氧化碳重整反应性能,针对镍负载量对反应活性和稳定性的影响进行了探讨。结果表明,随着镍负载量从2%增加到10%,催化剂的活性和稳定性均有所提高,但是当镍负载量进一步增加到20%时,催化剂的活性和稳定性略有下降。利用透射电子显微镜、X射线衍射和H2吸附脱附等手段对催化剂结构进行了表征,利用热重分析、拉曼光谱和透射电镜等手段对反应后回收的催化剂进行了表征。研究发现,随着镍负载量的增大,活性金属镍的颗粒粒径呈现增长趋势,并且在反应过程中显示出不同的失活方式。2%Ni/MgO(111)催化剂的失活原因主要以Ni粒子的氧化为主,而负载量大于2%的Ni/MgO(111)催化剂的失活原因则是以积炭为主。Abstract: The catalytic properties of MgO(111) nanosheet-supported Ni were investigated for the reforming of methane with carbon dioxide with the emphasis on the effect of nickel loadings. The catalytic activity and stability increased with increasing Ni loadings from 2% to 10%, while a further increase in the Ni loading from 10% to 20% led to a negative result. The TEM, XRD, H2-TPD, TG and Raman characterization results show that the deactivation behavior of Ni/MgO(111) depends on the amount of Ni, while the Ni particle size increased with increasing Ni loadings. The deactivation of the sample with 2% of Ni was probably caused by the Ni oxidation, whereas that of the catalyst with higher content of Ni was due to the deposition of carbonaceous materials.
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