NiO/MgO整体式催化剂上甲烷部分氧化制备合成气

Partial oxidation of methane to synthesis gas over monolithic NiO /MgO catalyst

甲烷部分氧化制备合成气反应过程具有反应速率快、能耗低和H2与CO物质的量比适用于合成甲醇及F-T合成等优点,是一种有希望替代传统水蒸汽重整的方法.研究在NiO/MgO蜂窝陶瓷整体式催化剂上的甲烷部分氧化过程,主要考察涂层载体、活性组分Ni含量、涂层载体前驱体、焙烧温度和还原温度对催化剂反应性能的影响.采用XRD、H2-TPR和N2吸附等表征前驱体及其负载活性组分NiO后的晶相、还原特性和吸附性能.结果表明,采用浸渍法制备催化剂时,Mg（NO3）2为涂层载体MgO前驱体,在NiO负载质量分数20％、焙烧温度（500～600）℃和还原温度750℃条件下制备的催化剂NiO/MgO-N性能较好,活性较稳定;以NiO/MgO-N为催化剂,在反应温度800℃、n（O2）∶ n（CH4）=0.5和空速9 723 h-1条件下,CH4转化率94.4％,H2选择性99.9％,CO选择性92.9％.

The catalytic partial oxidation of methane to syngas is currently considered a potential substitute for the existing steam reforming process,and has the advantages of fast reaction rate,low energy consumption and H2/CO molar ratio close to 2,which is ideal for downstream processes,such as methanol synthesis and F-T process.In this article,the partial oxidation of methane in honeycomb ceramic monolithic catalyst was studied.The effects of washcoats,active component NiO contents,MgO precursors,the temperatures of calcination and reduction on the catalytic performance of the catalysts were investigated.The as-prepared catalysts were characterized by N2 adsorption,X-ray diffraction and temperature-programmed reduction techniques.The results indicated that NiO/MgO-N catalyst exhibited better catalytic performance and activity stability,which was prepared by impregnation method and using Mg （NO3）2 as MgO precursor under the condition of NiO loading 20wt%,calcination temperature （500-600） ℃ and reduction temperature 750 ℃.CH4 Conversion,the selectivity to H2 and CO were 94.4%,99.9% and 92.9%,respectively,over NiO/MgO-N catalyst and under the process condition as follows：reaction temperature 800 ℃,n（O2） ∶ n （CH4） =0.5,and space velocity 9 723 h-1.