Effects of CeO2 addition on Ni/Al2O3 catalysts for the reaction of ammonia decomposition to hydrogen
Effects of CeO2 addition on Ni/Al2O3 catalysts for the reaction of ammonia decomposition to hydrogen
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DOI：
10.1016/j.apcatb.2007.11.008
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发表时间：
2008-04
影响因子：
22.1
通讯作者：
Weiqing Zheng;Jian Zhang;Q. Ge;Hengyong Xu;Wenzhao Li
中科院分区：
文献类型：
--
作者：
Weiqing Zheng;Jian Zhang;Q. Ge;Hengyong Xu;Wenzhao Li
采用N2吸附/脱附、H2化学吸附、X射线衍射（XRD）、H2程序升温还原（H2-TPR）和NH3程序升温表面还原（NH3-TPSR）等物理化学方法，研究了CeO 2对Ni/Al 2 O3催化剂氨分解制氢性能的影响。结果表明，CeO 2的加入大大提高了Ni/Al 2 O3催化剂的氨分解制氢活性和稳定性。在823 K、30000 ml/（hgcat）NH3空速下，CeO 2促进的Ni/Al 2 O3催化剂的NH3转化率和H2生成速率分别达到98.3%和32.9mmol/（hgcat）。表征结果表明，CeO 2的加入增大了催化剂的孔隙，缓和了Ni与Al 2 O3之间的相互作用，抑制了Ni 0晶粒的烧结，促进了N原子从Ni 0表面的复合脱附.
Effects of CeO2addition on the catalytic performance of Ni/Al2O3catalysts for ammonia decomposition to hydrogen were investigated by activity studies and some physico-chemical methods like N2-adsorption/-desorption, H2-chemisorption, X-ray diffraction (XRD), H2temperature-programmed reduction (H2-TPR) and NH3temperature-programmed surface reduction (NH3-TPSR). The results showed that the addition of CeO2greatly improved the catalytic activity and stability of Ni/Al2O3catalysts for ammonia decomposition to COx-free hydrogen. 98.3% NH3conversion and 32.9mmol/(mingcat) H2formation rate were achieved over CeO2promoted Ni/Al2O3catalyst at 823K and 30000ml/(hgcat) NH3space velocity. The characterization results indicate that the addition of CeO2enlarged the catalyst pores, moderated the interaction between Ni and alumnia, suppressed Ni0crystallites from sintering, and improved the recombinative desorption of N adatoms from the Ni0surface.