化工进展2024，Vol.43Issue(3)：1309-1317,9.DOI:10.16085/j.issn.1000-6613.2023-0447
HZSM-22的粒径调控及Pt/HZSM-22的正十二烷加氢异构催化性能
Particle size regulation of HZSM-22 and Pt/HZSM-22 for n-dodecane hydroisomerization
摘要
Abstract
ZSM-22 zeolite crystals with different c-axis lengths were synthesized by using supersaturated solution method under static hydrothermal conditions and adjusting the water content in the synthetic solution.The as-synthesized ZSM-22 zeolite crystals were characterized by XRD,SEM,N2 physical adsorption,NH3-TPD and Fourier transformed infra-red spectroscopy of pyridine adsorption(Py-FTIR).By loading Pt on the ZSM-22 zeolite crystals,the Pt/ZSM-22 bifunctional catalysts were prepared,in which ZSM-22 zeolite crystals played the role of acid supports and the 0.5%Pt acts as(de)hydrogenation active sites.The hydroisomerization of n-alkanes was carried out with n-dodecane as the probe molecules.The effect of water content in the zeolite synthesis solution on the hydroisomerization performance of Pt/ZSM-22 catalyst was investigated.The results indicated that the less the water,the smaller the ZSM-22 crystals.However,a few cristobalite and ZSM-5 crystals were formed when the content of water in the synthetic solution was reduced to a certain value.HZSM-22 synthesized in the solution with the molar composition of SiO2∶Al2O3∶K2O∶DEA∶H2O=1∶0.01∶0.08∶0.29∶28 showed the highest medium and strong Brønsted acid amount in the three HZSM-22 samples,and shorter c-axis length.The bifunctional catalyst Pt/HZSM-22 prepared with this kind of HZSM-22 crystals showed the best catalytic performance.The conversion of n-dodecane was 73.24%,the yield of iso-alkanes was 57.92%,and the selectivity of iso-alkanes was 79.09%.Moreover,the selectivity of mono-branched iso-dodecane with methyl branching positioned in the center of the chain,5-methylundecane,was up to 17.66%at 320℃.关键词
过饱和溶液法/ZSM-22分子筛/c轴长度/正十二烷/加氢异构化Key words
supersaturated solution method/ZSM-22 molecular sieve/c-axis length/n-dodecane/hydroisomerization分类
化学化工引用本文复制引用
陈风,王宣德,黄伟,王晓东,王琰..HZSM-22的粒径调控及Pt/HZSM-22的正十二烷加氢异构催化性能[J].化工进展,2024,43(3):1309-1317,9.基金项目
国家重点研发计划(2020YFB0606405) （2020YFB0606405）
山西省基础研究计划(20210302123197) （20210302123197）
山西省重点研发计划(201803D121043). （201803D121043）
