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

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2 400 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%。

Research on the performance of Cu/ZnO@H-β-P catalyst in the reaction of LPG preparation from syngas

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.