Li-Ni-La-O系复合氧化物催化剂上甲烷氧化偶联的研究  

Oxidative Coupling of Methane over Li-Ni-La-O Catalysts

作　　者：刘宝春[1] 远松月[1] 王连驰 于作龙[1] 

机构地区：[1]中国科学院长春应用化学研究所,长春130022

出　　处：《高等学校化学学报》1993年第11期1573-1577,共5页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金

摘　　要：考察了Li-Ni-La-O系催化剂的组成、结构及反应条件对甲烷氧化偶联反应活性的影响.在780℃、CH_4:O_2:N_2=2:1:7、空速15000h^(-1)时,C_2烃收率可达25.8％.XRD、IR、XPS及SEM等的结构分析表明,在LiLa_(1-x)Ni_xO_2催化剂中,当0.1≤x≤0.9时,该催化剂由LiNiO_2和LaNi_(1-y)Li_yO_(4-λ)两相组成,x<0.3时出现了LiLaO_2相,La_2Ni_(1-y)Li_yO_(4-λ)是甲烷氧化偶联的主要活性相,活性位Li^+-O^--Ni^(2+)数量的增加是活性提高的主要原因.LiNiO_2和LiLaO_2也有催化活性,它们与La_2Ni_(1-y)Li_yO_4间的协同作用也可能是催化活性增强的原因.The oxidative coupling of methane was studied over the Li-Ni-La-O mixed oxide cata-lysts. The effects of the catalyst composition and the reaction conditions on the activited of catalysts were examined. A higher C2 yield of 25. 8% was obtained at 780℃ and 15000 h-1.The surface and bulk structures of the catalysts were characterized by means of XRD, IR, XPS, SEM. The results clearly indicate that in the series of catalysts LiLa1-xNixO2, when 0. 1≤ x≤0. 95 the catalyst was composed of two phases La2Ni1-yLiyO4-λ and LiNiO2. When x<0. 3, LiLaO2 phase appeared. Among them La2Ni1-yLiyO4-λ possessed much higher catalytic activity for methane-oxidative coupling. The increase of the content of active site Li+-O--Ni2+ was the main factor for increasing the catalytic activity of methane-oxidative coupling. The synergeatic effect of different phases in the catalysts is also supposed.

关 键 词：甲烷 氧化偶联 锂镍镧氧化物 

分 类 号：O623.11[理学—有机化学]