Synthesis of mesoporous high‐silica zeolite Y and their catalytic cracking performance  

介孔高硅Y沸石的合成及催化裂化性能

作　　者：Wenhao Cui Dali Zhu Juan Tan Nan Chen Dong Fan Juan Wang Jingfeng Han Linying Wang Peng Tian Zhongmin Liu 崔文浩;朱大丽;谭涓;陈南;樊栋;王娟;韩晶峰;王林英;田鹏;刘中民(中国科学院大连化学物理研究所,洁净能源国家实验室(筹),甲醇制烯烃国家工程实验室,辽宁大连116023;中国科学院大学,北京100049;大连理工大学化工与环境生命学部,化学工程学院,催化化学与工程系,辽宁大连116024)

机构地区：[1]National Engineering Laboratory for Methanol to Olefins,Dalian National Laboratory for Clean Energy,Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian 116023,Liaoning,China [2]University of Chinese Academy of Sciences,Chinese Academy of Sciences,Beijing 100049,China [3]Department of Catalysis Chemistry and Engineering,School of Chemical Engineering,Faculty of Chemical,Environmental and Biological Science and Technology,Dalian University of Technology,Dalian 116024,Liaoning,China

出　　处：《Chinese Journal of Catalysis》2022年第7期1945-1954,共10页催化学报（英文）

基　　金：国家自然科学基金(21991090,21991091);中国科学院前沿科学重点研究项目(QYZDB-SSW-JSC040);中科院大连化学物理研究所自主部署基金(DICP ZZBS201807).

摘　　要：Mesoporous high‐silica zeolite Y with advantages of improved accessibility of acid sites and mass transport properties is highly desired catalytic materials for oil refinery,fine chemistry and emerg‐ing biorefinery.Here,we report the direct synthesis of mesoporous high‐silica zeolite Y(named MSY,SiO_(2)/Al2O_(3)≥9.8)and their excellent catalytic cracking performance.The obtained MSY mate‐rials are mesoporous single crystals with octahedral morphology,abundant mesoporosity and ex‐cellent(hydro)thermal stability.Both the acid concentration and acid strength of H‐form MSY are obviously higher than those of commercial ultra‐stable Y(USY),which should be attributed to the uniform Al distribution of MSY zeolite.The H‐MSY displays an obviously reduced deactivation rate and improved catalytic activity in the cracking reaction of bulky 1,3,5‐triisopropylbenzene(TIPB),as compared with its mesoporogen‐free counterpart and USY.In addition,H‐MSY was investigated as catalyst for the cracking of industrial heavy oil.The MSY‐based catalyst(after aging at 800 oC in 100%steam for 17 h)exhibits superior conversion(7.64%increase)and gasoline yield(16.37%increase)than industrial fluid catalytic cracking(FCC)catalyst under the investigated conditions.Y型沸石拥有三维十二元环孔道(孔径0.74 nm)以及超笼结构(直径1.12 nm),在石油冶炼、石油加工、精细化学品合成以及新兴生物油的炼制方面具有重要应用.研究表明,随着Y沸石骨架硅铝比(SiO_(2)/Al_(2)O_(3),简称SAR)提高,酸中心强度增加,酸密度降低,有助于抑制裂化反应中积碳导致催化剂的失活,并提高催化剂活性;另外,随着沸石骨架硅铝比提高,Y沸石对应热/水热稳定性相应增加,有利于保持催化剂长周期使用性能.Y沸石的大孔结构使其在工业应用中有着显著的优势,然而对于大分子反应物,反应物与沸石内部活性位点的接触以及相应的产物扩散仍限制了其催化性能.介孔沸石同时具有微孔和介孔两类孔道结构,可以克服微孔沸石有限孔径尺寸带来的传质限制,进一步提高反应性能.现在工业上应用的高硅Y沸石均是通过酸脱铝,水蒸汽辅助脱铝等后处理方法获得.虽然后处理过程可以提高沸石骨架硅铝比,并引入适量的介孔结构,改善其在催化裂化反应中的传质性能,但后处理过程工序复杂,耗时耗能,而且会形成脱铝梯度,不利于其催化应用.相对而言,直接合成介孔高硅Y沸石是最理想的途径.本文以商用双亲性有机硅烷作为介孔模板剂,采用晶核、有机模板剂与低碱度协同作用(NOA-co)策略一步直接合成介孔高硅Y沸石(MSY).研究了投料硅铝比、介孔剂加入量以及加入顺序对催化性能的影响.实验发现,产品的介孔孔容、外比表面积以及SAR随着介孔剂加入量的增加而逐渐提高,当介孔剂添加过量时无法得到纯相.合成的介孔高硅Y沸石具有高SAR(9.8‒12.6)和介孔孔容(0.13‒0.22 cm^(3)/g).选取SAR=10.7的介孔高硅Y沸石样品(MSY_(10.7))进行进一步研究.扫描电镜及透射电镜结果表明,MSY沸石具有典型八面体形貌、丰富的晶内介孔及优异的热/水热稳定性,晶粒中铝分布均匀.与商用USY沸石相比,MS

关 键 词：Mesoporous zeolite FAU SYNTHESIS High‐silica zeolite Y Fluid catalytic cracking 

分 类 号：TE624.91[石油与天然气工程—油气加工工程]