Cr2O3/ZrO2催化剂的构筑及其对CFC-12的低温催化水解性能

Cr2O3/ZrO2 catalyst for low-temperature catalytic hydrolysis of CFC-12: Performance, mechanism and regeneration

  • 摘要: 采用共沉淀法制备了Cr2O3/ZrO2复合催化剂,用于CFC-12的低温催化水解. 优化制备条件(Cr/Zr摩尔比1.00꞉1.00,500 ℃焙烧)下,催化剂具有介孔结构和高比表面积(248.01 m2/g),表面酸碱性位点均衡(总酸量0.45 mmol/g,总碱量0.32 mmol/g). 在温和条件(100 ℃)下,CFC-12水解率达99.84%,连续反应24 h后活性仍保持70%以上. XRD、N2吸脱附、NH3/CO2-TPD等表征表明,高度分散的Cr2O3与四方相ZrO2之间的酸碱协同效应是优异催化性能的关键,该效应同时促进了C—Cl键断裂和H2O分子活化. 失活催化剂经200 ℃焙烧再生后,活性恢复率达99.03%. 研究为氟利昂治理提供了一种稳定、可再生的环境友好型催化剂.

     

    Abstract: A Cr2O3/ZrO2 composite catalyst was synthesized via co-precipitation for low-temperature catalytic hydrolysis of CFC-12. The optimal preparation conditions (Cr/Zr molar ratio = 1.00∶1.00, calcination at 500 ℃) yielded a mesoporous material with a high specific surface area of 248.01 m2/g and balanced acid-base sites (total acid: 0.45 mmol/g, total base: 0.32 mmol/g). Under mild conditions (100 ℃), the catalyst achieved 99.84% hydrolysis efficiency of CFC-12 and maintained >70% activity after 24 h on stream. Characterization (XRD, N2 physisorption, NH3/CO2-TPD) revealed that the high performance originates from the acid-base synergistic effect between highly dispersed Cr2O3 and tetragonal ZrO2, which facilitates C–Cl bond cleavage and H2O activation. The deactivated catalyst was efficiently regenerated by calcination at 200 ℃, restoring 99.03% of its initial activity. This work demonstrates the potential of Cr2O3/ZrO2 as a stable, regenerable, and environmentally safe catalyst for Freon abatement.

     

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