Improvement of a Mesh-Type Cu/Ni/γ-Al2O3/Al Catalyst for Steam Reforming of Dimethyl Ether by Metal (Fe, Zn or La) Addition for CO in Situ Removal

摘要

A mesh-type structured anodic alumina supported Cu/Ni bi-functional catalyst was developed for steam reforming of dimethyl ether (SRD). It was found that the Cu/Ni/γ-Al _{style="font-family:Verdana;">2} style="font-family:Verdana;">O _{style="font-family:Verdana;">3} style="font-family:Verdana;">/Al catalyst had remarkable catalytic activity and stability, but a high CO selectivity. Therefore, a multi-functional catalyst was proposed by metals (Fe, Zn, or La) addition to inhibit CO formation during the SRD process. The results show that promoter Fe can improve the Cu dispersion and decrease the reduction temperature of catalyst, and CO selectivity was minimized from 27% to around 3%. However, the addition of Zn and La style="font-family:" white-space:normal;"=""> style="font-family:Verdana;">only can decrease the CO selectivity to 12%. Furthermore, there was an excellent synergetic effect between Cu/Ni/γ-Al _{style="font-family:Verdana;">2} style="font-family:Verdana;">O _{style="font-family:Verdana;">3} style="font-family:Verdana;"> and Fe over the style="font-family:Verdana;"> Cu/Ni/Fe/γ-Al _{style="font-family:Verdana;">2} style="font-family:Verdana;">O _{style="font-family:Verdana;">3} style="font-family:Verdana;">/Al catalyst by evaluating catalytic performance of catalysts with different packing structures. And the synergetic mechanism of the active components (γ-Al _{style="font-family:Verdana;">2} style="font-family:Verdana;">O _{style="font-family:Verdana;">3} style="font-family:Verdana;">, Cu or Cu _{style="font-family:Verdana;">2} style="font-family:Verdana;">O, and Fe _{style="font-family:Verdana;">3} style="font-family:Verdana;">O _{style="font-family:Verdana;">4} style="font-family:Verdana;">) for SRD and CO style="font-family:Verdana;">in suit style="font-family:Verdana;"> removal was proposed. Finally, a 400-h durability test was carried out and the results show that the style="font-family:" white-space:normal;"=""> style="font-family:Verdana;">Cu/Ni/Fe/γ-Al _{style="font-family:Verdana;">2} style="font-family:Verdana;">O _{style="font-family:Verdana;">3} style="font-family:Verdana;">/Al catalyst had an excellent stability with a 100% DME style="font-family:Verdana;"> conversion and low CO selectivity.