平板状阳极氧化铝催化剂在煤油水蒸汽重整中的催化性能

在草酸溶液中对一种铝基板(Al/Fe-Ni-Cr alloy/Al)采用阳极氧化技术制备了氧化铝多孔膜,考察了扩孔处理、水热处理和焙烧处理对氧化铝膜比表面积的影响,并用FE-SEM、BET等研究了氧化铝膜的微观形态及结构。采用这种材料作为载体通过浸渍法制备了负载钌质量分数1.0%的钌基催化剂Ru/Al,并在固定床反应器上研究Ru/Al催化剂在煤油水蒸汽重整中的催化性能。结果表明,在氧化铝多孔膜载体制备过程中,扩孔处理能有效扩大膜孔,水热处理能让多孔膜形成更为复杂的多孔结构,并极大地提高多孔膜的比表面积。在空气中750℃焙烧50 h后,多孔膜的比表面积仍能维持在原来的60%。催化剂性能测试结果表明,与对比剂Ru A相比,在活性实验中虽然两者活性相似,但在加速劣化实验中,采用阳极氧化技术制备的催化剂Ru/Al比Ru A更稳定。工业应用中对这种载体仍需要改良以减弱烧结程度,因为在水蒸汽气氛于750℃焙烧50 h后,载体的比表面积只有原来的38%。

Catalytic performance of a plate-type anodic alumina catalyst for kerosene steam reforming

A plate-type alumina support Al₂O₃/Fe-Ni-Cr alloy/Al₂O₃ was prepared in oxalic acid solution by anodization technology.The influence of pore widening treatment,hydrothermal treatment and calcination treatment on BET specific surface area of the support was investigated.The morphology and structure of the anodic alumina layer was characterized by FE-SEM,BET and other techniques.Ru/Al catalyst with ruthenium mass fraction 1.0% was prepared by using the porous anodic alumina support and impregnation method.Its performance for kerosene steam reforming reaction to hydrogen was investigated in a fixed bed reactor.The results showed that during the support preparation,pore diameter of the support was enlarged effectively by pore widening treatment.The BET specific surface area of the support could be enhanced greatly due to more complicated structure formation of the support by hydrothermal treatment.After it was calcined at 750 ℃ for 50 h in air,60% specific surface area of the porous anodic alumina support was remained.The results of reforming reactivity test indicated that the activity between anodic alumina catalyst Ru/Al and reference catalyst RuA were similar in activity experiment.However,the stability of Ru/Al catalyst was superior to that of RuA catalyst in the accelerated deactivation test.Nevertheless,for commercial application,some efforts should be made to reduce the sintering of anodic supports,because only 38% of the support surface area was kept after hydrothermal treatment at 750 ℃ for 50 h.