Pd/γ-Al2O3催化剂对烟气中多环芳烃的氧化性能研究

Oxidation characteristics of polycyclic aromatic hydrocarbons in flue gas over Pd/γ-Al2O3 catalyst

  • 摘要:  实验采用等体积浸渍法制备了系列Pd/γ-Al2O3催化剂。采用模拟实验装置并结合XRD、N2吸/脱附、TEM、H2-TPR和SEM-MAPS等手段对催化剂的组成及结构进行了表征,系统地考察了各催化剂对燃煤烟气中PAHs的催化氧化性能。结果表明,催化剂对烟气中PAHs排放总量的氧化效率为67.3%~93.5%,且烟气中PAHs的转化率随着Pd负载量的增加而提高;而催化剂的氧化性能随着PAHs环数(3~6)的增加而提高,对烟气中各PAHs排放毒性当量去除率超过90%。其中,Pd负载量为0.2%、催化剂焙烧温度为600℃条件下制备的催化剂具有最佳的PAHs消除性能,PAHs的氧化效率可达93.5%。

     

    Abstract:  A series of Pd/γ-Al2O3 catalysts with various Pd loadings was prepared via incipient-wetness impregnation method under different synthesis conditions. The structural and textural properties of the synthesized catalysts were characterized by XRD, N2 adsorption/desorption, TEM, H2-TPR, and SEM-MAPS; their catalytic performance in the elimination of polycyclic aromatic hydrocarbons (PAHs) in coal-fired flue gas by oxidation was investigated. The results revealed that the PAHs removal efficiency over various Pd-loaded catalysts fluctuates between 67.3% and 93.5%; the conversion of PAHs increases with the Pd loading in the catalyst. Moreover, a better oxidation activity of these catalysts is observed for the PAHs with higher ring-cycles; nevertheless, the removal rates based on the toxicity equivalence quantity (TEQ) for all PAHs are higher than 90%. The Pd/γ-Al2O3 with a Pd loading of 0.2% and calcined at 600℃ exhibits the best catalytic performance for PAHs oxidation, with a removal rate of 93.5% at 300℃.

     

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