摘要
采用浸渍法制备钴基催化剂,考察了催化剂焙烧温度对其F-T合成反应性能和产物分布的影响。制备催化剂时,不对催化剂进行焙烧,Co物种容易还原,并可较好分散,催化剂具有较高的催化活性和重质烃选择性。较高温度下焙烧,Co物种和载体间的相互作用增强,形成难还原的铝酸钴化合物,同时氧化钴晶粒聚集或烧结,Co物种的还原程度下降,催化剂CO加氢活性降低,重质烃选择性下降。在原料气n(H2)∶n(CO)=2.0、483K、1.5MPa和800h-1条件下,未焙烧、673K和923K焙烧的催化剂上进行F-T合成反应,CO的转化率分别为80.27%、78.41%和61.14%,重质烃的选择性C5+分别为88.54%、88.57%和77.95%。较低焙烧温度有利于反应速率的提高和重质烃的合成,较高焙烧温度使CO加氢活性下降,有利于低碳烃的生成。
Ru-Co-ZrO2/γ-Al2O3 catalysts were prepared using impregnation method. Influence of calcination temperature on their catalytic properties and product distribution for Fischer-Trposch synthesis was investigated. The catalysts prepared without calcination had easily-reducible cobalt species and good dispersion, and exhibited higher activity and selectivity to heavier hydrocarbons. Calcination at higher temperature resulted in stronger interaction between cobalt species and γ-Al2O3 support, less reducible cobalt aluminate, and lower activity and selectivity to heavier hydrocarbons due to aggregation or sintering of cobalt oxide crystals. CO conversion of 80.27%, 78.41% and 61. 14% and selectivity to C5^＋ of 88.54%, 88. 57% and 77. 95%, respectively, were obtained for Fischer-Tropsch synthesis under n（ H2 ）：n（CO） = 2. 0, 483 K, 1.5 MPa and 800 h^-1 over uncalcined catalyst, those calcined at 673 K and 923 K. It was concluded that lower calcination temperature favored increasing of reaction rate and formation of heavier hydrocarbons; higher calcination temperature lowered CO hydrogenation activity and favored formation of lower carbon hydrocarbons.
出处
《工业催化》
CAS
2008年第11期17-20,共4页
Industrial Catalysis
基金
博士学科点专项科研基金(20050251006)
