A novel synthesis process from CO and CO_2 to form alcohol over copperlanthanide complex catalysts

研究了复合氧化物Cu_6O_8Ln （NO_3）及其衍生物（Ln：镧系元素）的混合加氢催化剂体系。这种复合氧化物在氢气气氛下容易分解，形成金属铜和镧系元素的二元体系。重点研究了该体系在甲醇合成和乙烯加氢反应中的催化行为。以Cu (NO_3) _2和Yb (NO_3) _3为原料，在700 K O_2吹气条件下热分解制备Cu_6O_8Yb （NO_3）复合氧化物。用XRD对所制备的氧化物配合物的结构进行了验证。在反应前，以Cu_6O_8Yb （NO_3）为原料，在H_2气氛下按规定温度分解制备Cu-Yb_2O_3。采用闭式气体循环系统跟踪反应。用GLC对反应混合物进行分析。采用XRD、XPS和TEM-EDS对催化剂形貌进行了表征。在Cu- yb_2o_3和Cu/ZnO/Cr_2O_3三元组分催化剂上进行CO加氢。在573 K下，由相应的络合氧化物制备Cu-Yb_2O_3。CO加氢的主要产物为甲醇，对甲醇的选择性在95%以上。除氢化反应外，还观察到CO_2的生成。从反应的时间过程来看，CO_2在初始阶段有选择性地形成，活性随反应时间的增加而降低。周期2h后不断产生甲醇。在473K时，Cu- yb_2o_3表现出最大的活性，是Cu/ZnO/Cr_2O_3三元组分催化剂活性的4倍。由于Cu-Yb_2O_3是由Cu_6O_8Yb （NO_3）分解得到的，其活性与制备温度有关。523 K预处理的催化剂活性最高。研究了催化剂的形态，阐明了预处理与催化活性的关系。

We inestigated such a novel catalyst system for hydrogenation as the mixture of complex oxide, Cu_6O_8Ln (NO_3), derivatives (Ln : lanthanide). This complex oxide canbe easily decomposed under hydrogen atmosphere form binary system of copper metal and lanthanide. We forcus on the catalytic behavior of the system investigated in the methanol systhesis and the hydrogenation of ethylene.The complex oxide of Cu_6O_8Yb (NO_3) was prepared by thermal decomposition of Cu (NO_3) _2 and Yb (NO_3) _3 mixture under O_2 blowing at 700 K.The structure of the prepared oxide complex was confirmed by XRD.Cu-Yb_2O_3 was then prepared by the decomposition of Cu_6O_8Yb (NO_3) under H_2 atmosphere at prescribed temperature before the reaction.A closed gas circulation system was used to follow the reaction. The reactionmixtures were analyzed by GLC.The catalyst morphology was observed by XRD,XPS and TEM-EDS.CO hydrogenation was carried out over Cu-Yb_2O_3 and the ternary component catalyst, Cu/ZnO/Cr_2O_3. Cu-Yb_2O_3 was prepared from the corresponding complex oxide at 573 K.The main product of CO hydrogenation was methanol and the selectivity for methanol was more than 95 %. The formation of CO_2 was observed other than the hydrogenation. Judging from the time course of the reaction, CO_2 selectively formed at the initial stage and the activity decreased with increasing the passing time. Methanol produced constantly after the period for 2h. We have confirmed that the activity did not decrease over 50 h. At 473K,the Cu-Yb_2O_3 showed maximum activity, which is four times higher than that of the ternary component catalyst, Cu/ZnO/Cr_2O_3.Since Cu-Yb_2O_3 is prepared from the decomposition of Cu_6O_8Yb (NO_3), the activity would be dependent on the preparation temperature. The catalyst pretreated at 523 K showed the maximum activity. The catalyst morphology was studied to elucidate the relationship between the catalytic acftivity and the pretreatment.