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在Y分子筛上浸渍0.1 wt%Pd和0.1–0.5 wt%Ni,用X射线衍射表征了该催化剂的结晶度,用透射电镜测得平均金属粒径.催化剂中Pd和Ni的化学态用X射线光电子能谱测定,其酸性则用氨-程序升温脱附进行了表征,发现一些酸位被Ni~(2+)离子交换.采用程序升温还原表征了HY分子筛负载的Pd,Ni和Pd-Ni催化剂的还原性能.正癸烷加氢异构化反应在200–450℃和1 atm条件下进行.结果发现,当0.1 wt%Pd/HY中Ni添加量增至0.3 wt%时,正癸烷转化率和异构化选择性增加.单支链和双支链异构体选择性的增加表明该反应遵循质子化环丙烷中间体机理.Ni添加量超过阈值导致活性和异构化选择性急剧下降.综上可见,双金属催化剂更有利于选择性生成双支链异构体,其辛烷值更高.
The Y zeolite was impregnated with 0.1 wt% Pd and 0.1-0.5 wt% Ni, the crystallinity of the catalyst was characterized by X-ray diffraction and the average metal particle size was measured by transmission electron microscopy.The chemical states of Pd and Ni in the catalyst were characterized by X-ray The results of photoelectron spectroscopy showed that the acidity was characterized by ammonia-temperature programmed desorption and found that some acid sites were exchanged by Ni 2+ ions. The Pd, Ni and Pd-Ni supported on HY molecular sieve were characterized by temperature programmed reduction Reduction performance of n-decane hydroisomerization was carried out at 200-450 ℃ and 1 atm.The results showed that when the addition amount of Ni in 0.1 wt% Pd / HY increased to 0.3 wt%, n-decane The selectivity and selectivity for both the conversion and the isomerization are increased.The selective increase of the single and double-branched isomers indicates that the reaction follows the protonated cyclopropane intermediate mechanism.Ni additions above the threshold lead to drastic selectivity of activity and isomerization In conclusion, the bimetallic catalyst is more conducive to the selective production of double-branched isomers with higher octane number.