化工学报 ›› 2021, Vol. 72 ›› Issue (9): 4685-4697.DOI: 10.11949/0438-1157.20201937

• 催化、动力学与反应器 • 上一篇    下一篇

介孔构建对CuY甲醇氧化羰基化反应活性的影响

梁家豪1(),张国强1,高源2,尹娇1,郑华艳1,李忠1()   

  1. 1.太原理工大学煤科学与技术教育部和山西省重点实验室,山西 太原 030024
    2.潞安化工集团有限公司,山西 长治 046204
  • 收稿日期:2020-12-29 修回日期:2021-03-19 出版日期:2021-09-05 发布日期:2021-09-05
  • 通讯作者: 李忠
  • 作者简介:梁家豪(1995—),男,硕士,582937351@qq.com
  • 基金资助:
    国家自然科学基金项目(U1510203);山西省重点研发计划国际合作项目(201803D421011)

Effect of mesoporous construction on catalytic performance of CuY methanol oxidative carbonylation

Jiahao LIANG1(),Guoqiang ZHANG1,Yuan GAO2,Jiao YIN1,Huayan ZHENG1,Zhong LI1()   

  1. 1.Key Laboratory of Coal Science and Technology, Ministry of Education and Shanxi Province, Taiyuan University of Technology, Taiyuan 030024, Shanxi, China
    2.Luan Chemical Group Co. , Ltd. , Changzhi 046204, Shanxi, China
  • Received:2020-12-29 Revised:2021-03-19 Online:2021-09-05 Published:2021-09-05
  • Contact: Zhong LI

摘要:

采用H4EDTA、H2Na2EDTA和NaOH溶液对原始NaY分子筛分别进行单独酸碱改性和酸碱连续改性,并采用液相离子交换法制备相应的CuY催化剂。结合N2物理吸附、TEM、XRD、29Si NMR、27Al NMR、NH3-TPD、Py-IR、ICP、XPS和CO-FTIR等对载体和催化剂的结构进行表征,研究了NaY分子筛介孔构建对CuY催化甲醇氧化羰基化反应活性的影响。结果表明,NaY分子筛经H4EDTA单独处理后,部分骨架铝被脱除形成非骨架硅铝物种,得到的E-NaY并未形成明显的介孔;E-NaY经H2Na2EDTA酸洗处理后,非骨架铝和部分骨架铝被脱除,得到的EW-NaY具有明显的介孔结构;而E-NaY和EW-NaY经0.2 mol/L NaOH碱处理后,分子筛发生脱硅,同时伴随着非骨架铝重新插回分子筛骨架,得到的E0.2AT-NaY和EW0.2AT-NaY具有丰富的介孔结构。其中,EW0.2AT-NaY的介孔孔容(0.45 cm3/g)最大,且有丰富的Al缺陷结构,能够与反应物接触的Cu+交换位利用率最高。然而,由于EW0.2AT-NaY脱铝程度明显高于E0.2AT-NaY,导致能够与反应物接触的Cu+交换位数量(66 μmol/g)明显小于E0.2AT-NaY(176 μmol/g),最终导致EW0.2AT-CuY催化剂中Cu+活性位数量及催化活性略低于E0.2AT-CuY,二者的催化活性约为原始CuY催化剂的2.2倍。

关键词: 分子筛, 催化剂, 介孔, Cu+活性位, 氧化羰基化

Abstract:

H4EDTA, H2Na2EDTA and NaOH aqueous solutions were used to modify the original NaY zeolite separately by acid-base modification and continuous acid-base modification, and the corresponding CuY catalyst was prepared by the liquid-phase ion exchange method. The N2-physisorption, TEM, XRD, 29Si NMR, 27Al NMR, NH3-TPD, Py-IR, ICP, XPS and CO-FTIR were used to characterize the structure of the support and catalyst. The effect of mesoporous construction in NaY zeolite on catalytic performance of CuY for oxidative carbonylation of methanol was investigated. The results indicated that partial framework Al of NaY zeolite were extracted after sole treatment by H4EDTA, with the formation of extra-framework Si and Al species, and the obtained E-NaY did not form obvious mesoporous. Extra-framework and partial framework Al of E-NaY zeolite were removed after acid washing by H2Na2EDTA, and the obtained EW-NaY generated obvious mesoporous. The extracted Al species were reinserted back into the framework of zeolite accompanied with desilication during alkali treatment of E-NaY and EW-NaY by 0.2 mol/L NaOH, and abundant mesopores were formed in the obtained E0.2AT-NaY and EW0.2AT-NaY zeolite. Moreover, the utilization of exchanged sites for Cu+ accessible to reactants for EW0.2AT-NaY attained the maximum due to the highest mesopore volume (0.45 cm3/g) and abundant Al-defects structure. Nevertheless, the number of exchanged sites for Cu+ (66 μmol/g) accessible to reactants was significantly less than that of E0.2AT-NaY (176 μmol/g) due to higher dealumination degree of EW0.2AT-NaY than that of E0.2AT-NaY. Consequently, the number of Cu+ active sites and catalytic activity for EW0.2AT-CuY were just slightly lower than that for E0.2AT-CuY, and the catalytic activities for both were about 2.2 times as that of the pristine CuY catalyst.

Key words: zeolite, catalyst, mesopore, Cu+ active sites, oxidative carbonylation

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