Al源种类对微乳液法制备固体超强酸催化剂异构化性能的影响

分别以拟薄水铝石、γ-Al₂O₃、Al₂O₃、Al(NO₃)₃·9H₂O为Al源,通过微乳液法制备了一系列Pt-S₂₈O^2-/ZrO₂-Al₂O₃催化剂,并利用XRD、FT-IR、BET、H₂-TPR等手段对其进行了表征,考察了Al源种类对Pt-S₂₈O^2-/ZrO₂-Al₂O₃固体超强酸催化剂结构和酸性的影响,并以正戊烷异构化反应为探针,考察了Al源种类对催化剂异构化性能的影响。结果表明,不同Al源制备的催化剂均能够稳定ZrO₂四方晶相,增大催化剂的比表面积;除以拟薄水铝石为Al源制备的催化剂外,其他催化剂的氧化还原性能均有所提高。以Al(NO₃)₃·9H₂O为Al源制备的催化剂具有最大的比表面积和更多的超强酸,表现出最佳的异构化性能,在反应压力2.0 MPa、氢烃物质的量比4∶1、质量空速(WHSV)1.0 h^-1、反应温度220 ℃条件下,异戊烷产率达到59.5%。

Influence of aluminum species on the isomerization performance over solid superacid Pt-S2 O2-8/ZrO2-Al2 O3

A series of Pt-S₂₈O^2-/ZrO₂-Al₂O₃ catalysts were prepared by microemulsion method with pseudo-boehmite, γ-Al₂O₃, Al₂O₃ and Al(NO₃)₃·9H₂O as aluminum source, respectively, and the resulting catalysts were characterized by XRD, FT-IR, BET, H₂-TPR techniques. The influence of aluminum sources on the structure and acidic properties of the catalysts were investigated. The catalytic performance of the Pt-S₂₈O^2-/ZrO₂-Al₂O₃ catalysts was studied using n-petane isomerization as a probe reaction. The results indicated that all the catalysts prepared with different source of aluminum can stabilize the tetrogonal ZrO₂ phase and increase specific surface area of the catalysts. Except for pseudo-boehmite, the redox performance of catalysts prepared with other aluminum source were improved. The catalyst prepared with Al(NO₃)₃·9H₂O as the aluminum source, which possessed the largest specific surface area and more superacid, exhibited the best isomerization performance. At a reaction temperature of 220 ℃, a pressure of 2.0 MPa, a hydrogen/hydrocarbon mol ratio of 4∶1 and a WHSV of 1.0 h^-1, the isopentane yield reaches a maximum of 59.5%.