La_2O_3助剂对CH_4部分氧化制氢Ni-Cu/ZrSiO催化剂的影响  

EFFECT OF La_2O_3 ON Ni-Cu/ZrSiO CATALYST FOR PARTIAL OXIDATION OF METHANE TO PRODUCE HYDROGEN

作　　者：王爱菊[1] 钟顺和[1] 

机构地区：[1]天津大学化工学院,天津300072

出　　处：《燃料化学学报》2004年第1期73-77,共5页Journal of Fuel Chemistry and Technology

基　　金：国家重大基础研究前期研究专项基金(2001CCA03600)~~

摘　　要：用等体积浸渍法制备了ZrO2 SiO2(ZrSiO)表面复合氧化物负载的Ni Cu双金属催化剂,并用TPR、XPS、IR、TPD及微反技术考察了稀土La2O3助剂对CH4和H2O在Ni Cu/ZrSiO催化剂表面上的吸附及甲烷部分氧化制氢反应性能的影响。结果表明,加入La2O3助剂使催化剂表面Ni,Cu原子电子云密度增加,CH4和H2O在催化剂表面上的吸附增强;在反应温度450℃、进料摩尔比nCH4∶nH2O=1∶0 5∶2 5以及甲烷空速SV(CH4)=1200h-1的条件∶nO2下,催化剂Ni Cu La2O3/ZrSiO上CH4转化率大于90%,生成H2的选择性高于99%,副产物CO的选择性仅为1 1%。根据实验结果,讨论了La2O3助催化剂的作用机理。ZrO_2-SiO_2 (ZrSiO) supported Ni-Cu-La_2O_3 catalyst for CH_4 partial oxidation to produce hydrogen was prepared by isovolumetric impregnation. By using TPR, XPS, IR, TPD and microreactor techniques, the effect of La_2O_3 on adsorption and reaction of CH_4 with H_2O and O_2 on the catalyst were studied. The results showed that the addition of La_2O_3 has obvious influence on the electronic charge distribution of metal active sites Ni, Cu on Ni-Cu/ZrSiO catalyst, and increases the chemisorption intensity of CH_4 and H_2O. The main reaction products of CH_4 partial oxidation with H_2O and O_2 on Ni-Cu-La_2O_3/ZrSiO catalyst are H_2 and CO_2. Under condition of 450℃, n_(CH_4)∶n_(O_2)∶n_(H_2O)= 1∶0.5∶2.5 and SV(CH_4)=1200h^(-1), conversion of CH_4 (x_(CH_4)) is greater than 90%, selectivity of H_2 (S_(H_2)) is more than 99%, and S_(CO) is merely 1.1% on Ni-Cu-La_2O_3/MgSiO catalyst. Moreover, the catalysis mechanism of promoter La_2O_3 was discussed.

关 键 词：镧助剂 甲烷部分氧化 制氢催化剂 Ni-Cu/ZrrSiO 

分 类 号：O643[理学—物理化学]