设计合成了Rh/CeO2-SiC新型催化剂,X射线衍射和透射电镜等表征结果表明,SiC表面均匀分散了4nm左右的CeO2纳米颗粒,进而可很好地分散Rh纳米粒子.该催化剂在乙醇部分氧化制氢反应中显示出优越的催化性能,乙醇转化率及H2选择性随反应温度的提高而提高,700oC时乙醇转化率为100%,H2选择性为50%,CO选择性仅为13%,且反应40h未见明显失活,反应后催化剂表面没有明显的积炭生成.该催化剂上较低的CO选择性及抗积炭性能可归因于SiC的热传导性能以及CeO2中活泼晶格氧的作用.
An Rh catalyst supporting on CeO2-SiC composite has been designed for partial oxidation of ethanol for hydrogen production.X ray diffraction and transmission electron microscopy results show that CeO2 nanoparticles with an average size of 4m are well dispersed on SiC surface,which further acts as a support of Rh nanoparticles.The obtained Rh/CeO2-SiC catalyze efficiently partial oxidation of ethanol.At 700°C,the ethanol conversion is 100%,with a H2 selectivity of 50%,CO selectivity of 13%.No deactivation is observed within 40h time on stream.Furthermore,the ethanol conversion and the H2 selectivity increase with the rising temperature.No noticeable carbon deposition is observed on the catalyst after reaction.The rather low CO selectivity and little carbon deposition may be attributed to the unique property of good heat conductivity of SiC and the carbon elimination ability of CeO2 with active oxygen species.