Cu/ZnO@H-β-P催化剂在合成气制备液化石油气反应中的性能研究

摘要

采用共沉淀法制备Cu/ZnO催化剂、水热合成法制备H-β分子筛、通过物理包膜法制备了具有核壳结构的Cu/ZnO@H-β-P催化剂,并用于合成气制备液化石油气(LPG)反应.通过XRD、NH3-TPD、BET和SEM-EDS等手段对催化剂进行了表征,利用固定床连续反应装置对催化剂进行了活性评价.结果表明,Cu/ZnO@H-β-P催化剂是具有中孔的核壳结构材料,其协同作用打破了原有的热力学平衡,促进了甲醇→DME→LPG串联反应的连续进行.与物理混合的Mix-Cu/ZnO-H-β催化剂相比,Cu/ZnO@H-β-P催化剂的CO转化率和LPG选择性更高,空速和反应温度对催化剂活性影响明显,最佳空速和反应温度分别为2400 h-1和350℃.使用Cu/ZnO@H-β-P催化剂在最佳条件下进行合成气制备LPG反应,CO转化率达到了57.22％,LPG选择性达到了60.52％.%The Cu/ZnO catalyst was prepared by the coprecipitation method,and the H-β zeolite was prepared by the hydrothermal synthesis method,and the bifunctional catalyst Cu/ZnO@H-β-P with core shell structure was prepared by the physical envelope method.The catalysts were used in the reactions of LPG preparation from syngas.The catalysts were characterized by the means of XRD,BET,NH3-TPD and SEM-EDS.The activity of the catalysts was evaluated by a continuous flow fixed bed reactor.The results show that the Cu/ZnO@H-β-P catalyst was the mesoporous material with core shell structure,and the acid intensity of H-β zeolite was changed,and the cascade reactions from methanol to dimethyl ether to LPG were promoted by core-shell synergy in the Cu/ZnO@H-β-P catalyst.The CO conversion and LPG selectivity were higher on the Cu/ZnO@H-β-P catalyst with core shell structure than those on the Mix-Cu/ZnO-H-β catalyst.The catalyst activity was affected by the reaction conditions of space velocity and reaction temperature.The best space velocity and reaction temperature were 2 400 h-1 and 350 ℃.The CO conversion and LPG selectivity achieved respectively 57.22％ and 60.52％ in the reaction of LPG preparation from syngas at the best reaction conditions using the Cu/ZnO@H-β-P catalyst.