合成甲基叔丁基醚的沸石分子筛催化剂的研究

Study on Zeolite Catalysts Used for MTBE Synthesis

对合成甲基叔丁基醚 (MTBE)反应的几种沸石分子筛进行研究 ,认为催化剂的活性主要受催化剂的酸强度及酸中心数影响。催化剂酸性强 ,催化活性虽高 ,但MTBE选择性差 ;而中强酸中心是醚化反应的最佳酸中心。选择性与催化剂的结构和酸强度有关 ;对选择性较好的催化剂改性 ,增加中强酸的酸中心数 ,可以提高其活性。催化剂的使用寿命与催化剂酸性及结构有关。HY型和HUSY型分子筛的活性最高 ,但选择性差 ,寿命最短。而Hβ和HZSM -5分子筛活性较低 ,但选择性好 ,寿命较长。改性后的 β分子筛性能最佳。

Several zeolite catalysts used for the synthesis of MTBE from isobutene and methanol have been studied in this paper.The results show that the catalytic activity is mainly affected by the acid strength and number of acid center.The higher the acid strength is,the higher the catalytic activity and the lower the selectivity will be.A medium number of acid site suits best for the synthesis of MTBE.The selectivity is related to the porous structure and acid strength of the catalyst.Catalytic activity can be improved by increasing the number of medium-strong acid site.Catalytic stability also is related to the pore structure and acid strength of the catalyst.HY and HUSY zeolite catalyst are high in activity,but low in selectivity and stability,while Hβ and HZSM-5 zeolite catalysts are lower in activity,but high in selectivity and stability.Modified Hβ zeolite catalyst exhibits the best catalytic property.