镁、钐和锆对AlF_3催化剂的乙炔气相氢氟化反应性能的影响

Effects of Mg, Sm and Zr promoters on the performance of AlF_3 catalysts for vapor phase hydrofluorination of acetylene

研究了Mg、Sm和Zr助剂对AlF_3催化剂的乙炔气相氢氟化合成氟乙烯反应性能的影响。通过XRD、NH_3-TPD和拉曼光谱对催化剂进行了表征。结果表明,添加Zr既能保持C_2H_2的高转化率,提高氟乙烯选择性,同时能降低积炭选择性;加入Mg或Sm助剂,均使C_2H_2转化率下降,Mg大幅度降低积炭选择性,Sm提高了氟乙烯选择性。助剂的加入,改变了催化剂表面酸性位的数量和性能,是影响催化剂性能的主要因素。

The influence of Mg, Sm and Zr promoters on the properties of AlF3 catalysts for vapor phase hydrofluorination of acetylene to vinyl fluoride was investigated. The catalysts were characterized by XRD, NH3-TPD and Raman spectra. The results indicated that the addition of Zr could not only keep high conversion of C2H2 ,increase the selectivity to vinyl fluoride, but also reduce the selectivity to coke deposition compared with pure AlF3 catalyst. It was also found that both Mg and Sm promoters decreased the conversion of C2H2 ;the catalyst exhibited lower selectivity to coke deposition with the addition of Mg; the addtion of Sm enhanced the selectivity to vinyl fluoride. The addition of promoters changed the amount and performance of acidic sites on the surface of AlF3 catalyst and was the main influencing factor for the catalyst properties.