Co nanoparticles confined in mesopores of MFI zeolite for selective syngas conversion to heavy liquid hydrocarbon fuels  

MFI介孔分子筛限域封装Co纳米颗粒选择性催化合成气转化为重质液态烃燃料

作　　者：Neng Gong Quanzheng Deng Yujiao Wang Zitao Wang Lu Han Peng Wu Shun'ai Che 龚能;邓权政;王雨娇;王自陶;韩璐;吴鹏;车顺爱(同济大学化学科学与工程学院,上海200092;重庆大学化学化工学院,前沿交叉学科研究院,跨尺度多孔材料研究中心,重庆400044;吉林大学无机合成与制备化学国家重点实验室,吉林长春130015;华东师范大学化学与分子工程学院,上海市绿色化学与化工过程绿色化重点实验室,石油化工分子转化与反应工程全国重点实验室,上海200062;上海交通大学化学化工学院,变革性分子前沿科学中心,金属基复合材料国家重点实验室,上海市手性药物分子工程重点实验室,上海200240)

机构地区：[1]School of Chemical Science and Engineering,Tongji University,Shanghai 200092,China [2]Multi-scale Porous Materials Center,Institute of Advanced Interdisciplinary Studies&School of Chemistry and Chemical Engineering,Chongqing University,Chongqing 400044,China [3]State Key Laboratory of Inorganic Synthesis&Preparative Chemistry,Jilin University,Changchun 130015,Jilin,China [4]Shanghai Key Laboratory of Green Chemistry and Chemical Processes,State Key Laboratory of Petroleum Molecular&Process Engineering,School of Chemistry and Molecular Engineering,East China Normal University,Shanghai 200062,China [5]School of Chemistry and Chemical Engineering,Frontiers Science Center for Transformative Molecules,State Key Laboratory of Metal Matrix Composites,Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs,Shanghai Jiao Tong University,Shanghai 200240,China

出　　处：《Chinese Journal of Catalysis》2025年第1期246-258,共13页催化学报(英文)

基　　金：国家自然科学基金(21931008);国家重点研发计划(2021YFA1200301,2021YFA1501401).

摘　　要：Designing Fischer-Tropsch synthesis(FTS)catalysts to selectively produce liquid hydrocarbon fuels is a crucial challenge.Herein,we selectively introduced Co nanoparticles(NPs)into the micropores and mesopores of an ordered mesoporous MFI zeolite(OMMZ)through impregnation,which controlled the carbon number distribution in the FTS products by tuning the position of catalytic active sites in differently sized pores.The Co precursors coordinated by acetate with a size of 9.4×4.2×2.5Åand by 2,2‘-bipyridine with a size of 9.5×8.7×7.9Å,smaller and larger than the micropores(ca.5.5Å)of MFI,made the Co species incorporated in OMMZ's micropores and mesopores,respectively.The carbon number products synthesized with the Co NPs confined in mesopores were larger than that in micropores.The high jet and diesel selectivities of 66.5%and 65.3%were achieved with Co NPs confined in micropores and mesopores of less acidic Na-type OMMZ,respectively.Gasoline and jet selectivities of 76.7%and 70.8%were achieved with Co NPs confined in micropores and mesopores of H-type OMMZ with Brönsted acid sites,respectively.A series of characterizations revealed that the selective production of diesel and jet fuels was due to the C-C cleavage suppressing of heavier hydrocarbons by the Co NPs located in mesopores.费托合成(FTS)能有效地将非石油基碳资源衍生的合成气(CO/H_(2))转化为清洁液态烃燃料.目前FTS主要的活性金属组分是Fe,Ru和Co,其中,Co基催化剂具有适宜的长链烃生长能力和价格低廉等优点.采用介孔ZSM-5或者Y分子筛作为Co金属纳米颗粒(NPs)的载体,利用分子筛固有的酸性位点,增强传质能力和择形选择性,将固体蜡C_(21+)裂解为中间馏分液体燃料.由于重质的液态烃过度裂解和氢解,这些催化剂合成的液态产物通常是汽油烃(C_(5)-C_(11)).本文通过调控Co NPs在介孔MFI分子筛中的位置分布,抑制重质烃产物的C-C键过度裂解和氢解,以实现煤油(C_(8)-C_(16))和柴油(C_(10)-C_(20))的高选择性生成。本文采用浸渍法将CoNPs选择性地封装到有序介孔MFI分子筛(OMMZ)的微孔和介孔孔道中,通过调控不同尺寸孔道中催化活性位点的位置,实现了FTS产物中碳数分布的控制设计了醋酸盐配位Co(Co-acet)(9.4×4.2×2.5Å)和2,2-联吡啶配位Co(Co-bpy)(9.5×8.7×7.9Å)两种比MFI结构的10元环孔道(5.5Å)尺寸更小和更大的Co前驱体,使得Co分别进入OMMZ的微孔(Co-acet/OMMZ)和介孔孔道(Co-bpy/OMMZ).X射线衍射和高分辨扫描透射电镜结果表明,在Co-acet/OMMZ中,CoNPs主要以亚纳米纤维状限域在微孔孔道里,直径约为0.9nm;在Co-bpy/OMMZ中,CoNPs主要以纳米颗粒状限域在介孔孔道中,尺寸约为2.5nm.合成气转化反应结果表明,CoNPs限域在微孔和介孔孔道中的弱酸性Na型Co-acet/Na-OMMZ和Co-bpy/Na-OMMZ催化剂分别显示出66.5%的煤油选择性和65.3%的柴油选择性。CoNPs限域在具有Bronsted酸位点的H型Co-acet/H-OMMZ和Co-bpy/H-OMMZ催化剂时,分别显示了76.7%的汽油选择性和70.8%的煤油选择性.催化结果表明,在CoNPs位于OMMZ有序介孔中的Co-bpy/OMMZ上形成的烃类产物碳数比位于微孔中的Co-acet/OMMZ上形成的产物碳数高,意味着介孔中均匀分布的CoNPs可以缓解重质烃的C-C裂解,而且Co-bp

关 键 词：Fischer-Tropsch synthesis Heavy liquid hydrocarbon fuel Co nanoparticle Ordered mesoporous MFI zeolite C-C cleavage 

分 类 号：O64[理学—物理化学]