Cu催化剂的络合完全液相制备及催化性能研究
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摘要
为考察络合剂对Cu基催化剂形貌、结构和催化性质的影响,采用络合完全液相法制备CuZnAl催化剂,并用XRD、H_2-TPR、NH_3-TPD、CO_2-TPD对催化剂进行了表征。在浆态床中对催化剂的CO加氢反应性能进行了考察。结果显示,没食子酸络合完全液相法制备的CuZnAl催化剂展现出与传统甲醇催化剂不同的性能,乙醇选择性高(达11.1%),催化活性稳定,120h后CO转化率扔维持45%左右。表征结果显示,催化剂表面Cu~+和Cu~0共存,产生高的碱酸比是乙醇得以形成原因。这为制备低成本乙醇Cu基催化剂提供了另外一种研究途径。
In order to investigate the effect of complexing agent on the morphology, structure and catalytic properties of Cu-based catalysts, CuZnAl catalysts were prepared by complexation complete liquid-phase technology, and the catalysts were characterized by XRD, H_2-TPR, NH3-TPD and CO_2-TPD. The CO hydrogenation reaction performances of the catalysts were examined in a slurry bed.The results show that the CuZnAl catalyst prepared by the complete liquid-phase technology with gallic acid as complexing agent exhibits different performance from the traditional methanol catalyst, having high ethanol selectivity(up to 11.1%) and good catalytic activity stability. The CO conversion could be maintained at about 45% after 120 h. The characterization results indicate that the ethanol formation is attributed to the coexistence of Cu~+and Cu~0 on the catalyst surface and the high base-acid ratio of the catalyst.This provides an alternative approach to the preparation of low cost Cu-based catalysts for synthesis of ethanol.
In order to investigate the effect of complexing agent on the morphology, structure and catalytic properties of Cu-based catalysts, CuZnAl catalysts were prepared by complexation complete liquid-phase technology, and the catalysts were characterized by XRD, H_2-TPR, NH3-TPD and CO_2-TPD. The CO hydrogenation reaction performances of the catalysts were examined in a slurry bed.The results show that the CuZnAl catalyst prepared by the complete liquid-phase technology with gallic acid as complexing agent exhibits different performance from the traditional methanol catalyst, having high ethanol selectivity(up to 11.1%) and good catalytic activity stability. The CO conversion could be maintained at about 45% after 120 h. The characterization results indicate that the ethanol formation is attributed to the coexistence of Cu~+and Cu~0 on the catalyst surface and the high base-acid ratio of the catalyst.This provides an alternative approach to the preparation of low cost Cu-based catalysts for synthesis of ethanol.
引文
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[2]Poul L,Ammar S,Jouini N,et al.Synthesis of inorganic compounds(metal,oxide and hydroxide)in polyol medium:A versatile route related to the sol-gel process[J].J Sol-Gel Sci Technol,2003,26:261-265.
[3]Anˇzlovar A,Orel Z C,ˇZigon M.Copper(I)oxide and metallic copper particles formed in 1,2-propane diol[J].J Eur Ceram Soc,2007,27:987-991.
[4]Ning W S,Shen H Y,Liu H Z.Study of the effect of preparation method on Cu O-Zn O-Al2O3catalyst[J].Appl Catal A,2001,211:153-157.
[5]Barroso M N,Gomez M F,Gambo J A,et al.Preparation and characterization of Cu Zn Al catalysts by citrate gel process[J].J Phys Chem Solids,2006,67:1583-1589.
[6]Feng W,Wang Q W,Ji P J,et al.Carbon nanotubes coated on silica gels as a support of Cu-Co catalyst for the syngthesis of higher alcohols from syngas[J].Ind Eng Chem Res,2011,50:11067-11072.
[7]陶偌偈,臧双全,赵阁,等.草酰胺桥联大环二羰四胺铜(II)-钴((II)异双核配合物的合成、结构、表征和电化学性质[J].应用化学,2002,19(1):459-463.
[8]Lehmann M,Marcos M,Serrano J L,et al.Rigid chiral building blocks for copper(II)and palladium(II)-containing liquid crystals[J].Chem Mater,2001,13:4374-4381.
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[10]李志红,黄伟,左志军,等.用XPS研究不同方法制备的Cu Zn Al一步法二甲醚合成催化剂[J].催化学报,2009,30(2):171-177.