La修饰提高CO_(2)制甲醇催化剂Cu/ZnO/Al_(2)O_(3)的稳定性  

Promoted stability of Cu/ZnO/Al_(2)O_(3)catalysts for methanol production from CO_(2)hydrogenation by La modification

作　　者：牛萌萌 姜雅楠 张弦 张翠娟 刘源 NIU Mengmeng;JIANG Yanan;ZHANG Xian;ZHANG Cuijuan;LIU Yuan(Tianjing Key Laboratory of Applied Catalysis Science and Technology,School of Chemical Engineering and Technology,Tianjin University,Tianjin 300350,China;Ordos Carbon Neutral Research and Application Company Limited,Ordos 017000,China)

机构地区：[1]天津大学化工学院天津市应用催化科学与工程重点实验室,天津300350 [2]鄂尔多斯市碳中和研究应用有限公司,内蒙古鄂尔多斯017000

出　　处：《燃料化学学报（中英文）》2024年第8期1095-1102,共8页Journal of Fuel Chemistry and Technology

基　　金：国家自然科学基金(21872101,21962014);鄂尔多斯市重点研发计划(YF20232313);鄂尔多斯市产业创新人才团队和山西省区域合作项目(202204041101029)资助。

摘　　要：CO_(2)加氢制甲醇反应中Cu/ZnO/Al_(2)O_(3)催化剂的失活是限制其应用的主要原因之一,实验通过向Cu/ZnO/Al_(2)O_(3)催化剂中添加不同含量的La,合成了一系列La改性的Cu/ZnO/Al_(2)O_(3)催化剂,以提高其对CO_(2)加氢制甲醇反应的催化稳定性。在温度200℃,压力3 MPa,空速12000 mL/(g·h)条件下进行的100 h短期稳定性测试,未改性的Cu/ZnO/Al_(2)O_(3)催化剂在100 h内活性衰减明显,添加La后催化剂稳定性逐渐得到提高,当La添加量为5%时活性最佳(CO_(2)转化率4%,甲醇选择性85%),并且该催化剂在1000 h长期稳定性测试中表现出较高的稳定性(在190−220 h失活17%后保持稳定)。通过X射线衍射(XRD)、X射线光电子能谱(XPS)表征发现,加入5%La提高了Cu/ZnO/Al_(2)O_(3)催化剂中Cu、ZnO的分散度,抑制了催化剂中Cu的烧结;同时稳定了Cu^(0/+),延缓了催化剂中Cu的氧化,从而提高了催化剂的稳定性。Deactivation of Cu/ZnO/Al_(2)O_(3)catalysts in CO_(2)hydrogenation to methanol reaction is one of the main reasons limiting their application.We synthesized a series of La modified Cu/ZnO/Al_(2)O_(3)catalysts by adding different contents of La to improve the stability.In the 100 h short-term stability test at 200℃under 3 MPa with a GHSV of 12000 mL/(g·h),the unmodified Cu/ZnO/Al_(2)O_(3)catalysts degraded obviously over 100 h.In sharp contrast,the stability was significantly promoted by the addition of La.The best activity was achieved with 5%La added samples(4%CO_(2)conversion and 85%methanol selectivity),which also showed impressive stability over 1000 h except about 17%deactivation during the initial 190−220 h.The X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS)results revealed that the addition of 5%La improved the dispersion of Cu and Zn,inhibited the sintering of Cu,stabilized the Cu0/+species and retarded oxidation of Cu in catalysts,which attributed to the high stability of the catalysts.

关 键 词：Cu/ZnO/Al_(2)O_(3) La助剂 稳定性 

分 类 号：O643[理学—物理化学]