BaCO_3/La_2O_3催化剂低温甲烷氧化偶联及床层热点效应  

Low temperature oxidative coupling of methane over BaCO_3/La_2O_3 catalysts and thermal effect of catalyst bed

作　　者：丁大为[1] 季生福[1] 王开[1] 孙思[1] 唐晶晶[1] 李成岳[1] 

机构地区：[1]北京化工大学化工资源有效利用国家重点实验室,北京100029

出　　处：《天然气化工—C1化学与化工》2008年第4期6-12,共7页Natural Gas Chemical Industry

基　　金：国家重点基础研究规划(973)项目(批准号:2005CB221405)

摘　　要：以BaCO3和不同的镧化合物作为催化剂组分,分别采用干混法和湿混法制备了BaCO3质量含量为2.5%～15%的BaCO3/La2O3催化剂,在微型固定床反应器上评价了催化剂的甲烷氧化偶联反应性能,考察了反应条件对催化剂性能的影响,以及催化剂床层中的热点效应,采用XRD和TPR对催化剂的结构和性能进行了表征。结果表明,不同方法制备的BaCO3/La2O3催化剂在较低炉温的条件下都具有好的甲烷氧化偶联反应性能,其中湿混法制备的10%BaCO3/La2O3催化剂性能最好,在烷氧比为2,反应气体空速为36000 mL.g-1.h-1的条件下,反应炉温在125℃时甲烷氧化偶联反应仍能平稳进行。存在于催化剂床层的热点是维持甲烷氧化偶联反应的关键。不同方法制备的BaCO3/La2O3催化剂其物相和氧化还原性能也有一定的差别。A series of BαCO3/Lα2O3 catalysts with BαCO3 mass percentage of 2.5%-15% were prepared with different lanthanum compounds by dry or wet mixing method, and their catalytic activities for the oxidative coupling of methane （OCM） were evaluated in a fixed-bed micro-reactor. The structures of catalysts were characterized by XRD and TPR techniques. The results showed that the BαCO3/Lα2O3 catalysts had good low,temperature catalytic activities for OCM, and the 10 wtBαCO3/Lα2O3 catalyst prepared by wet mixing method showed the best catalytic activity, with which the OCM reaction could be hold at the furnace temperature of 125℃ when the CH4/O2 volume ratio was 2 and GHSV was 36000 mL·g^-12·h^-1. There were the hot spots in the catalyst bed and the thermal effect of catalyst bed played an important role in the low temperature OCM reaction over the BαCO3/Lα2O3 catalysts. The BαCO3/Lα2O3 catalysts prepared by different methods had some difference in the phase structure and redox property.

关 键 词：BαCO3/Lα2O3催化剂 甲烷氧化偶联 低温 热点效应 

分 类 号：O643[理学—物理化学]