Catalytic upgrading of waste PET to dimethyl cyclohexane-1,4-dicarboxylate over defective sulfonated UiO-66_(def)-SO_(3)H supported Ru catalyst  

废弃PET化学升级为DMCD的缺陷型磺酸化Ru/UiO-66_(def)-SO_(3)H催化剂

作　　者：Weitao Ou Yingdan Ye Yibin Zhang Huaiyuan Zhao Weichen Du Zhaoyin Hou 区维韬;叶莹丹;张艺濒;赵怀远;杜玮辰;侯昭胤(浙江大学化学系,生物质化工教育部重点实验室,浙江杭州310028;浙江恒逸石化研究院有限公司,浙江杭州311200)

机构地区：[1]Key Laboratory of Biomass Chemical Engineering of Ministry of Education,Department of Chemistry,Zhejiang University,Hangzhou 310028,Zhejiang,China [2]Zhejiang Hengyi Petrochemical Research Institute Co.,Ltd.,Hangzhou 311200,Zhejiang,China

出　　处：《Chinese Journal of Catalysis》2025年第4期363-374,共12页催化学报(英文)

基　　金：浙江省“尖兵”-“领雁”科技发展计划(2024C01045);国家自然科学基金(21773206);中央高校基本科研业务费专项基金(226-2022-00055).

摘　　要：Poly(ethylene glycol-co-1,4-cyclohexanedimethanol terephthalate)(PETG)possesses excellent properties and stability than traditional poly(ethylene terephthalate)(PET).However,the production and application of PETG are restricted by the expensive monomer(1,4-cyclohexanedimethanol,CHDM).Direct upgrading of waste PET to dimethyl cyclohexane-1,4-dicarboxylate(DMCD)can promote the production of CHDM in large scale.In this work,a bifunctional Ru/UiO-66_(def)-SO_(3)H catalyst was synthesized and utilized in coupled methanolysis(of waste PET to dimethyl terephthalate(DMT))and hydrogenation(of DMT to DMCD)under mild condition.Characterizations revealed that Ru/UiO-66_(def)-SO_(3)H possessed mesopores(dominant channels of 2.72 and 3.44 nm),enlarged surface area(998 m^(2)·g^(–1)),enhanced acidity(580μmol·g^(–1)),and Ru nanoparticles(NPs)dispersed highly(45.1%)compared to those of Ru/UiO-66.These combined advantages could accelerate the methanolysis and hydrogenation reactions simultaneously,promoting the performance of direct upgrading of PET to DMCD in one pot.In particular,the conversion of PET and yield of DMCD over Ru/UiO-66_(def)-SO_(3)H reached 100%and 97.7%at 170℃and 3 MPa H_(2)within 6 h.Moreover,Ru/UiO-66_(def)-SO3H was also capable for the upcycling of waste PET-based products including beverage bottles,textile fiber and packaging film to DMCD.对苯二甲酸-乙二醇-1,4-环己烷二甲醇共聚酯(PCT/PETG)以及对苯二甲酸-四甲基环丁二醇-环己二醇共聚酯(PCTG)具有耐热性高、韧性好、抗冲击、透明和可回收等优势,广泛用于婴儿制品、儿童玩具、高端显示材料和高性能粉末涂料等领域.然而,合成上述共聚酯的关键单体1,4-环己烷二甲醇(CHDM)严重依赖进口,价格昂贵,传统的对苯二甲酸二甲酯(DMT)两步加氢制备CHDM需要使用贵金属(Pd)催化剂,工艺条件苛刻.直接采用废弃聚对苯二甲酸乙二醇酯(PET)为原料化学升级制备CHDM及其关键中间体1,4-环己烷二甲酸二甲酯(DMCD)可以取代昂贵的DMT原料,研制可以实现这个过程的催化剂和反应机理具有十分重要的意义和应用前景,这也是目前废弃聚酯转化方向的研究热点.针对PET的链状结构、中间产物(DMT)的分子体积大(1.32-1.37nm)、“一锅”法化学升级制备DMCD需要醇解活性中心和加氢活性中心的协同作用以及适宜的孔径和表界面特性等.本文制备了缺陷型磺酸化UiO-66_(def)-SO_(3)H负载的Ru基催化剂(Ru/UiO-66_(def)-SO_(3)H),成功地利用该催化剂实现了废弃PET“一锅”法化学升级制备DMCD的新工艺.表征结果显示,与传统的微孔型Ru/UiO-66催化剂相比,Ru/UiO-66_(def)-SO_(3)H中生成了规则的介孔孔道(2.72和3.44 nm),具有较大的比表面积和孔体积(分别为998 m^(2)·g^(–1)和0.83 cm^(3)·g^(–1)),酸量大(580μmol·g^(–1)),亲/疏水性(接触角为22.9°)适宜,Ru与载体(Zr-O)相互作用较强,Ru分散度高(45.1%)等优势.Ru/UiO-66_(def)-SO_(3)H催化剂在单独的PET醇解到DMT,以及DMT加氢到DMCD过程中都具有较好的活性,这主要归因于配位不饱和Zr-O节点的暴露以及-SO_(3)H的引入可以增加酸性位点(PET醇解活性位点)的数量,介孔孔道有利于DMT/DMCD等的扩散,亲水性能提升能够增强带有末端羟基的PET及其低聚物的吸附,而且Ru的分散度高,与载体的强相互

关 键 词：Waste plastic refinery Poly(ethylene terephthalate) Upcycling Dimethyl cyclohexane-1 4-dicarboxylate Ru/UiO-66_(def)-SO_(3)H 

分 类 号：TQ426.94[化学工程]