B_2O_3/ZrO_2催化剂在气相环己酮肟重排反应中的稳定性和再生性能

Zirconia with high surface area (247 m 2/g) obtained by digesting sol gel of hydrous zirconia was used as a carrier of the B 2O 3/ZrO 2 catalyst for the gas phase Beckmann rearrangement of cyclohexanone oxime to form caprolactam. Effects of boria loading and activation calcination temperature on the catalyst performance were investigated. The optimization of the boria loading and the calcination temperature leads to a highly stable and regenerable B 2O 3/ZrO 2 catalyst for the rearrangement reaction. When the boria loading is 26 9% and the catalyst is calcined at 600 ℃, the B 2O 3/ZrO 2 shows the best performance, and it has been one of the best solid catalysts for the gas phase Beckmann rearrangement so far.

氧化硼对菱镁矿尾矿合成镁橄榄石晶体结构与性能的影响

在工业废弃物菱镁矿尾矿中加入石英砂和少量B_2O_3,通过固相反应烧结合成镁橄榄石材料,探讨B_2O_3对合成镁橄榄石材料晶体结构与性能的影响。利用XRD、SEM对合成镁橄榄石的相组成、晶胞参数、显微结构等进行研究。结果表明:由于B_2O_3的引入,促进了镁橄榄石晶体结构中缺陷的生成,导致镁橄榄石晶胞参数和晶胞体积减小,加快了反应离子间交换扩散速度,形成顽火辉石和透辉石等高温液相,促进了烧结,提高了材料的体积密度,降低了显气孔率。