摘要
应用 XRD,TPR,H2 -TPD技术研究焙烧温度对 Ni O/δ-Al2 O3催化剂性能的影响。结果表明 ,随着焙烧温度的增高 ,Ni O与载体 Al2 O3之间相互作用逐渐增强 ,直至最后生成 Ni Al2 O4 尖晶石。同时表明 ,随着焙烧温度的提高 ,催化剂的还原温度明显增高。另外 ,TPR结果还表明 Ni Al2 O4 仅仅是与载体发生强相互作用的那部分 Ni O进一步进入 Al2 O3晶格的结果 ,而游离态的 Ni O不参与形成 Ni Al2 O4 。通过催化剂的甲烷部分氧化制合成气反应性能评价 ,发现低温焙烧样品活性较高 ,与上述表征结果相关联 ,说明还原态的 Ni物种是该反应的活性相。
A study of effects on nickel alumina catalysts of calcination temperature was carried out by using X rays diffreaction,TPR and H 2 TPD.Results show that free NiO reduces readily to form Ni crystallites,whereas NiAl 2O 4 reduces with difficulty.The TPR profiles also suggested that NiAl 2O 4 was formed by reaction with NiO that interacts strongly with support,namely,fixed NiO,instead of free NiO.The catalytic performance for partial oxidation of methane to syngas over nickel alumina catalysts calcined in different temperature is presented.The results demonstrate that partial oxidation of methane to syngas calls for the presence of metallic nickel sites.Therefore,high temperature calcination is undesirable for the utilization of nickel alumian catalysts in the partial oxidation of methane to syngas.
出处
《化学研究与应用》
CAS
CSCD
2000年第5期521-524,共4页
Chemical Research and Application
基金
国家自然科学基金! ( 2 97730 2 8)
国家重点基础研究发展规划资助!项目 ( G19990 2 2 4 0 7)
