Zr(SO₄)₂/?-Al₂O₃ And Its Rare-earth Modified Catalysts Are Effective For 1- Study On The Catalytic Performance Of Butene Oligomerization

Transition metal salt supported solid acid catalysts for oligomerization of 1-butene to dimer C₈and trimer C₁₂olefins were studied.The Zr(SO₄)₂/?-Al₂O₃catalyst with Zr(SO₄)₂supported on?-Al₂O₃was prepared,and the catalytic performance of different Zr(SO₄)₂loadings for oligomerization of 1-butene was investigated;for Zr(SO₄)₂/?-Al₂O₃catalyst with better loading ratio,the improvement of catalyst performance by adding rare earth cocatalysts was discussed through RE(Ce,La).The method of changing acidity and distribution by adding H₂SO₄into the impregnated carrier solution was also discussed to improve the catalytic performance of the catalyst.The oligomerization of 1-butene was carried out in a self-built continuous fixed bed reactor with online chromatographic analysis.The acid distribution of the catalyst was characterized by NH₃-TPD,and the specific surface area,pore diameter and pore volume of the catalyst were characterized by BET pore specific surface area analyzer.Combined with the data of acid distribution and structure characterized by physical properties,the performance of the catalyst was further discussed.The results show that the catalyst studied has activity on the oligomerization of 1-butene to produce dimer C₈and trimer C₁₂,and the loading of active component Zr(SO₄)₂has a significant effect.When the?-Al₂O₃loading is 0.75mmol/g,the 1-butene conversion rate is 56.33%,the product is mainly dimer,and the dimer selectivity is 99.02%;modified by adding CeO₂,La₂O₃,CeO₂+La₂O₃,respectively.The prepared multi-component catalyst has improved surface acidity and greatly improved the problem of catalyst deactivation caused by carbon on the surface of the catalyst,so that1-butene can undergo oligomerization under the action of the catalyst.Among them,the CeO₂-Zr(SO₄)₂/?-Al₂O₃catalyst modified with CeO₂is the most suitable catalyst for 1-butene oligomerization.The 1-butene conversion rate can reach 70.05%and the dimerization product selectivity is 85.74%.Auxiliary addition of H₂SO₄modified 0.0685CeO₂-0.5Zr(SO₄)₂-SO₄^2-/?-Al₂O₃(mmol/g)catalyst 1-butene conversion rate 71.91%,dimerization product selectivity 98.10%.