La-Cu/ZnO/ZrO_(2)催化剂上CO_(2)加氢合成甲醇性能研究

Study on the performance of CO_(2) hydrogenation tomethanol on La-Cu/ZnO/ZrO_(2) catalysts

采用共沉淀法制备了不同含量La掺杂的Cu/ZnO/ZrO_(2)催化剂,并对其进行了关于CO_(2)加氢合成甲醇的实验研究。采用XRD、N_(2)物理吸附、N_(2)O化学吸附、XPS、H_(2)-TPR、CO_(2)-TPD等技术考察了La对于Cu/ZnO/ZrO_(2)催化剂的优势,并对La不同含量的影响进行了研究。详细讨论了不同掺杂量(0%~10%)La的加入对Cu平均粒径、聚集状态和元素间相互作用的影响。实验表明,掺杂的La后,Cu/ZnO/ZrO_(2)催化剂的比表面积和分散度显著提高,碱性位点的数量显著增加与未经改性的催化剂相比具有明显的甲醇选择性优势。La的掺杂促进了Cu-ZnO之间相互作用,提升了催化性能。适宜的La含量有利于Cu/ZnO/ZrO_(2)催化剂的催化性能,当La含量为5%时,在240℃、3 MPa的条件下CH_(3)OH的时空产率最高达到了0.35(g(MeOH)/g(cat)·h)。

Cu/ZnO/ZrO_(2)catalysts doped with different contents of La were prepared by the co-precipitation method and experimentally investigated with respect to the synthesis of methanol by CO_(2)hydrogenation.The advantages of La for Cu/ZnO/ZrO_(2)catalysts were investigated by XRD,N_(2)physisorption,N 2O chemisorption,XPS,H_(2)-TPR,and CO_(2)-TPD,and the effects of different contents of La were investigated.The effects of the incorporation of different dopant amounts(0%-10%)of La on the average particle size,aggregation state,and the interaction of the elements of Cu were discussed in detail.The experiments showed that the specific surface area and dispersion of the Cu/ZnO/ZrO_(2)catalysts were significantly increased by the doped La,and the number of basic sites was significantly increased compared with that of the unmodified catalysts with an obvious advantage of methanol selectivity.The doping of La promoted the Cu-ZnO interactions and enhanced the catalytic performance.The appropriate La content is favorable to the catalytic performance of the Cu/ZnO/ZrO_(2)catalysts,and the highest spatial and temporal yield of CH 3OH reached 0.35(g(MeOH)/g(cat)·h)at 240℃and 3 MPa with 5%La content.