论文部分内容阅读
采用熔融法制备了掺杂Mn的Cu/Zn/Al_2O_3催化剂,用于CO_2加氢合成甲醇。考察了元素组成对催化剂结构和性能的影响。通过扫描电子显微镜(SEM)、X射线能谱仪(1EDS)、X射线衍射仪(XRD)、比表面积分析仪(BET)等对制备的催化剂进行了表征。结果表明:熔融法制备的催化剂为合金固溶体(ss),合金化程度较高;随着Mn含量的增加,Cu在合金中的分布更加分散;晶格常数随着Mn含量的增加而增大;当Cu占合金总质量的40%时,催化剂的晶格常数最大,甲醇选择性最高,约为35.8%。催化剂合金化后,甲醇的选择性明显提高,这可能归因于合金催化剂表面的缺陷较多。合金通常具有优良的耐腐蚀和耐高温性能,其在CO_2加氢合成低碳醇方面具有潜在的应用价值。
A Cu / Zn / Al_2O_3 catalyst doped with Mn was prepared by a melting method and was used for the hydrogenation of CO_2 to methanol. The effect of elemental composition on the structure and properties of the catalyst was investigated. The prepared catalysts were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (1EDS), X-ray diffraction (XRD), specific surface area analyzer (BET) The results show that the catalyst prepared by the melting method is alloy solid solution (ss), and the degree of alloying is high. With the increase of Mn content, the distribution of Cu in the alloy is more dispersed. The lattice constant increases with the increase of Mn content. When Cu accounted for 40% of the total mass of the alloy, the largest lattice constant of the catalyst, the highest methanol selectivity, about 35.8%. After the catalyst alloying, methanol selectivity increased significantly, which may be due to the surface of the alloy catalyst more defects. Alloy usually has excellent corrosion resistance and high temperature performance, which has potential applications in the hydrogenation of CO_2 to lower alcohols.