Abstract:

The effects of 0.5％ Pt/γ-Al₂O₃ catalysts with different K promoters for preparing o-phenylphenol (OPP) from o-cyclohexenylcyclohexanone dehydrogenation were studied.These catalysts were characterized by XRD, H2-TPD, NH₃-TPD, CO₂-TPD techniques.The results showed that the addition of K decreased the acidity, basicity and the volume of absorbed hydrogen.The 6.00%K₂SO₄ promoter weakened the acid-base strength and decreased the acid-base sites.It also adjusted the adsorption of intermediate products, OPP and volume of hydrogen, prohibited the formation of byproducts, and obviously improved the selectivity of OPP.The conversion of o-cyclohexenylcyclohexanone reached 100% and the selectivity of o-phenylphenol was more than 90% with 0.12 h^-1 of LHSV and 33 ml·g^-1·h^-1 H₂ flow rate at 380℃.

Key words:

邻苯基苯酚, 环己烯基环己酮, 脱氢, Pt催化剂, K助剂

摘要：

通过加入不同K助剂对0.5% Pt/γ-Al₂O₃催化剂进行改性，考察了其在由环己烯基环己酮脱氢制邻苯基苯酚（OPP）的催化反应中的催化性能，利用XRD、H₂-TPD、NH₃-TPD、CO₂-TPD等手段对催化剂进行表征，并与反应结果关联。研究表明，Pt/γ-Al₂O₃催化剂加入K助剂后不同程度地减少了催化剂表面的酸、碱量和对氢的吸附量;采用6.00%K₂SO₄作为助剂，明显地弱化了催化剂表面的强酸和强碱中心，减少了酸、碱量，调整了催化剂表面对中间产物、OPP和氢吸附量，抑制了副反应，可显著提高生成OPP的选择性，在LHSV 0.12 h^-1、H₂空速33 ml·g^-1·h^-1、380℃的反应条件下，环己烯基环己酮转化率为100%，OPP选择性达90%以上。

关键词:

邻苯基苯酚, 环己烯基环己酮, 脱氢, Pt催化剂, K助剂