镍调变六铝酸盐LaNi_yAl_(12-y)O_(19-δ)催化甲烷部分氧化制合成气的研究  

STUDY ON Ni-MODIFIED HEXAALUMINATE CATALYST LaNi_yAl_(12-y)O_(19-δ)FOR PARTIAL OXIDATION OF METHANE TO SYNGAS

作　　者：赵丽娜[1] 洪军[1] 崔运成[1] 牛玉[1] 

机构地区：[1]吉林师范大学化学学院,吉林四平136000

出　　处：《精细石油化工》2008年第1期1-5,共5页Speciality Petrochemicals

基　　金：吉林省教育厅科研计划项目(200570)。

摘　　要：采用高温焙烧硝酸盐氧化物分解法,通过同晶取代作用,把过渡金属活性组分镍镶嵌在六铝酸盐晶体的晶格中,制备了一系列镍调变六铝酸盐复合氧化物LaNi_yAl_(12-y)O_(19-δ)催化剂,通过XRD、TPR、XPS等手段,考察了镍调变六铝酸盐LaNi_yAl_(12-y)O_(19-δ)的体相结构、氢还原性、表面性质和对甲烷部分氧化制合成气反应催化活性。六铝酸盐LaNiAl_(11)O_(19-δ)的体相结构在经过900℃还原前后基本保持不变,基于结合能数据和TPR实验可推断Ni的价态为Ni^(2+),且调变镍本身的价态不随其调变量的改变而改变。实验表明,还原六铝酸盐LaNi_yAl_(12-y)O_(19-δ)展示了良好的催化活性,在500～800℃反应温度范围内,甲烷和氧气的转化率随温度的升高而迅速增大,当870℃时,甲烷和氧气的转化率均可达到100%。在相同反应条件下,对不同调变量镍催化剂,其催化活性随镍调变量(y值)的增大而提高。该法制得的六铝酸盐催化剂在甲烷部分氧化制合成气反应中具有良好的稳定性和催化活性,并具有很好的应用前景。A series of Ni-modified hexaaluminate oxides, LaNiyAl12-yO19-δ（y=0, 0.2, 0.4, 0.6, 0.8 and 1.0） were prepared by the decomposition of nitrates, calcination at high temperatures and substituting the metals in the crystal lattice of hexaaluminate. The catalysts were characterized using XRD, XPS, TPR, etc. , and studied in the partial oxidation of methane into syngas. The results showed that the hexaaluminate oxides obtained by the method of pyrolysis exhibited the same crystal structure after being reduced at 900 ℃ ; Nickel had the valence of 2＋ without changing. The conversions of CH4 and 02 increased markedly with the increase of the temperature in the range of 500 ℃ to 800 ℃. When the reaction temperature was 870 ℃, both the conversions of CH4 and O2 reached to about 100%. Under the same experimental conditions, the catalytic activity of the hexaaluminate oxides increased when the value of y changed from 0.2 to 1.0. The hexaaluminate oxides have the potentiality due to their good activity and stability in the partial oxidation of methane to syngas.

关 键 词：六铝酸盐LaNiyAl12-yO19—δ 催化剂 镍调变 甲烷部分氧化 合成气 

分 类 号：TQ426[化学工程] O643[理学—物理化学]