甲烷氧化偶联催化反应的特征  

CHARACTERIZATON OF METHANE OXIDATIVE COUPLING WITH TEMPERATURE PROGRAMMED REACTION

作　　者：汤才林 臧璟龄 徐竹生[1] 林励吾[1] 

机构地区：[1]中国科学院大连化学物理研究所,大连116023

出　　处：《Chinese Journal of Catalysis》1993年第6期426-430,共5页催化学报（英文）

摘　　要：应用程序升温反应(TPR)及质谱分析表征了CaO,Sm_2O_3,0.5—10 ％Sm/CaO催化剂上的甲烷氧化偶联反应特性。谱图分析表明,在400—1000℃范围内,甲烷氧化偶联反应产物的变化呈现三个反应温度区域:(1)完全氧化区,反应主要为CH_3·在催化剂表面完全氧化形成COx和H_2;(2)偶联区,主要为CH_3·的氧化和偶联竞争反应,H_2谱线出现明显的低温峰;(3)氧耗尽区,反应为高温气相反应,产物主要为CO与H_2。在Sm/CaO催化剂上随Sm含量的增加,H_2峰温度与氧耗尽温度具有相似的变化规律。The temperature programmed reaction (TPR) combined with MS analyzer has been used to characterize the oxidative coupling of methane over CaO, Sm2O3 arid 0.5-10% Sm/CaO eatalysts. The reactants and products curves of TPR data suggest that in the temperature range of 400-1000℃,three regions are observed according to the different reaction processes, composition of products and mechanism. ( 1 ) Completely oxidative region:CH3 is completely oxidized on the catalyst surface, both COx and H2 are produced; (2) coupling region., the competition of CH3-oxidation with coupling is the main reaction, the H2 line in TPR shows a peak at low temperature; (3)O2 wholly consumed region, at the temperature higher than 850℃, the concentration of oxygen in the reactor tends to become zero, while the reaction is nearly in the gas phase and CO and H2 are the main products. The above results illustrate that the peak temperature of H2 curves and the temperature at which O2 is completely consumed plotted against the amount of Sm doped for the Sm/CaO catalyst show the same shape and both have the lowest temperature at the point of 2% Sm.

关 键 词：甲烷 氧化偶联 程序升温反应 

分 类 号：O623.11[理学—有机化学]