摘要
本工作研究了球形硅铝氧化物负载的铂-钯(Pt-Pd)贵金属催化剂的加氢活性和抗氮性能。首先,以过量共浸渍法制成5种不同负载量的Pt-Pd贵金属催化剂,元素分析结果表明浸渍液中Pt的质量分数升高会显著提高催化剂上Pt的负载量并明显降低Pd的负载量,而浸渍液中Pd的质量分数的升高对Pt、Pd的负载量几乎无影响;进一步的分析发现浸渍液的组成不仅影响催化剂上活性物的含量和分布,而且会造成催化剂孔结构的差异。其次,以四氢萘作为原料,在连续固定床反应器中对AS-1、AS-4和AS-5等3种催化剂的加氢活性和抗氮性能进行考评,实验结果表明,Pt负载量最高的AS-5催化剂的加氢活性和抗氮性能最好,Pt负载量居中的AS-4催化剂加氢活性最差而抗氮性能居中,Pt负载量最低的AS-1催化剂加氢活性居中而抗氮性能最差。结合能谱分析结果发现当载体上的Pt呈厚蛋壳型分布和Pd呈蛋白型分布时,催化剂的加氢活性和抗氮性能最优。最后,对AS-5催化剂的稳定性进行考评实验,发现当原料中的氮含量提高到50 ppm,连续反应45 h后,十氢萘的收率仍大于80%。实验结果表明,AS-5催化剂具有良好的加氢抗氮稳定性。
In this paper,hydrogenation activity and nitrogen resistance of Pt-Pd catalysts loaded in a kind of spherical Si-Al oxide as a carrier was studied.First,five kinds of impregnating solution with different Pt and Pd content was used to prepare the Pt-Pd catalysts with dip-drain technique.The actual Pt and Pd load were measured by element analysts.and the results showed that when Pt content of impregnating solution increase,Pt load would rise significantly and the Pd load would drop distinctly.However,Pd content of impregnating solution seemed play no roles on the Pt and Pd load in catalysts.Further analysis revealed that different constitutions of impregnating solution changed the pore structure as well as the noble metal load and its distribution in the carrier of catalysts.Second,the three catalysts with clear different Pt and Pd load were used to test tetralin＇s hydrogenation activity and their nitrogen resistance in a fixed-bed reactor.It was shown that the catalyst with most Pt load showed highest hydrogenation activity and greatest resistance to nitrogen;the catalyst with medium Pt load showed poorest hydrogenation activity and medium resistance to nitrogen;and catalyst with lowest Pt load showed medium hydrogenation activity and poorest resistance to nitrogen.EDX was used to analyze Pt and Pd＇s radial distribution in the carrier,the results showed that when Pt formed a kind of ＇thick eggshell＇ distribution and Pd formed a kind of ＇egg white＇ distribution,the catalyst showed highest hydrogenation activity and greatest resistance to nitrogen.Last,the catalyst＇s stability to naphthalene hydrogenation was tested,and the result showed that when the nitrogen content rised 50 ppm,the yield of decalin was over 80% after 45 hours＇ continuous hydrogenation,which meaned the Pt-Pd catalyst could steadily perform hydrogenation in a low nitrogen feed.
出处
《化学反应工程与工艺》
CAS
CSCD
北大核心
2011年第5期393-399,共7页
Chemical Reaction Engineering and Technology
关键词
铂-钯催化剂
过量浸渍法
加氢
抗氮
十氢萘合成
Platinum-Palladium catalyst
dip-drain technique
hydrogenation
nitrogen resistance
synthesis of decalin
作者简介
秦磊（1986-）,男,硕士研究生；
阳永荣（1962-），男，教授，通讯联系人。E-mail：yangyr@zju.edu.cn
