【摘要】 采用水热合成-负载法制备了Ni/Ce-Zr-Al-Ox催化剂,进行了CO2重整CH4的反应,并采用X射线光电子能谱(XPS)、程序升温加氢(TPH)等方法表征了在反应过程中催化剂表面的积碳物种,考察了添加少量水蒸汽对积碳的影响以及水蒸汽和表面积碳物种的作用.TPH实验测得有两类碳物种,一类是在250～350℃出现的少量α-碳,应主要是活性高的CH4解离碎片;另一类是在700℃附近出现的β-碳,应是导致催化剂失活的趋于石墨化或已经石墨化的积碳.β-碳比α-碳更容易同水蒸汽作用,添加少量水蒸汽到反应气中能够明显抑制β-碳的生成.活性测试结果表明,Ni/Ce-Zr-Al-Ox催化剂显示了89%的CH4转化率和良好的稳定性,添加3.2%(φ)的水蒸汽后活性提高到94%,由于对非活性积碳的抑制,可以预料其稳定性也将进一步提高.更多还原

【Abstract】 A Ni /Ce-Zr-Al-O x catalyst was prepared by hydrotherm al synthesis-impregnation method.The CO 2 reforming of CH 4 reaction was performed.By XPS and TPH methods the carbon species deposited on the surface of catalyst during the reaction were characterized;The effect on the carbon deposit by adding a small amount o f steam in feed gas and the interaction between steam and carbon species were studied.The results obtained show that there are mainly two types of carbon species :α-carbon appearing at 250～350℃shoul d be mainly CH 4 decomposed fragment which shows rea ctive to hydrogenation;β-carbon appearing at about 700℃should be the unreactive carbon which tends to be g raphite or is graphitized carbon and is responsible for catalyst deactiv ation.β-carbon is easier to react with steam thanα-carbon,therefore adding a small am ount of steam in feed gas can obviously suppressβ-carbon deposit.The activity test s hows that the Ni /Ce-Zr-Al-O x catalyst has a CH 4 con-version of 89%and a good stability,a nd the CH 4 conversion increases to 94%by addin g 3.2%(φ)steam.In addition,due to the suppression to u nreactive carbon,it can be expected that the stability of catalyst will b e further promoted.更多还原