Ni/Al2O3催化甲烷裂解

分别通过浸渍法和共沉淀法制备了不同Ni负载量的Ni/Al2O3催化剂。考察了Ni负载量、制备方法以及反应温度对Ni/Al2O3催化甲烷裂解性能的影响。结果表明,在550℃,浸渍法制备的Ni/Al2O3催化剂,当Ni负载量为20%(质量分数)、Ni金属平均粒径为11.25 nm时,具有最佳的甲烷催化裂解效果,其每摩尔Ni的氢气产量和每克Ni碳产量分别为164 mol和15.30 g。催化剂制备方法对Ni/Al2O3甲烷催化裂解反应有显著影响,相同Ni负载量共沉淀法制备的Ni/Al2O3甲烷催化裂解总体效果要好于浸渍法制备的Ni/Al2O3,而且反应过程中生成的碳纤维较长,管径也较均一。550℃时,共沉淀法制备的Ni负载量为41.2%(质量分数)的Ni/Al2O3催化剂在反应至350 min时,仍保持着30%以上的转化率。

The Methane Catalytic Decomposition over Ni/Al2O3

Ni/Al2O3 catalysts have been prepared through either impregnation or coprecipitation methods.The effects of Ni loading,preparation method and reaction temperature on the methane catalytic decomposition have been investigated.The results indicated that 20%(mass fraction) Ni/Al2O3 of which the average particle size of Ni was about 11.25 nm showed the best catalytic performance among the impregnated catalysts.The yields of carbon for per gram Ni and hydrogen for per mole Ni on such catalyst were 15.30 g and 164 mol,respectively.On the coprecipitated Ni/Al2O3,both the catalytic activity and lifespan of catalyst were improved.The deposited filamentous carbon over coprecipitated Ni/Al2O3 was much longer and more homogeneous than that generated over impregnated Ni/Al2O3.The methane catalytic conversion on coprecipitated Ni/Al2O3(41.2% mass fraction)remained higher than 30% after running the reaction at 550 ℃ up to 350 min.