关键词: 烷烃, 异丁烷, 脱氢, 氧化铝, 催化剂, 硼改性

Abstract: Boron modified K₂O-Cr₂O₃/γ-Al₂O₃ catalysts were prepared by incipient impregnation. The resulting catalysts had 2% of K₂O and 12% of Cr₂O₃, but different B amout and were investigated under 560℃, isobutane GHSV of 400h-1 and atmosphere in a fixed-bed reactor for its performance in isobutane dehydrogenation. Meanwhile, the catalysts were characterized by means of BET, XRD, NH₃-TPD and O₂-TPO. The results showed that, the addition of B had no significant influence on the structure of the catalysts, but efficiently adjusted the surface acidity of the catalysts, which thereby inhibited the side reaction of cracking and carbon formation, and improved the isobutene selectivity and stability in consequence. However, too much addition of B would result in the aggregation of Cr₂O₃, leading to a decrease of isobutane conversion considering the catalytic activity, stability and isobutene selectivity of the catalysts, we proposed the proper B capacity was around 1.0%.

Key words: alkane, isobutane, dehydrogenation, alumina, catalyst, boron modification