摘要
采用3种不同的沉淀方式(正加、反加和并流)制备出3个具有相同组成的甲醇合成催化剂样品CuO/ZnO/Al2O3,它们的活性顺序为:并流法样品>反加法样品>正加法样品;还原温度由低到高的顺序为:反加法样品<并流法样品<正加法样品。通过对催化剂前驱物进行DTA分析,证实了3种沉淀过程中相应的Cu2+和Zn2+的沉淀行为,即在并流和反加沉淀过程中,Cu2+和Zn2+同时均匀地沉淀,而在正加沉淀过程中,Cu2+和Zn2+发生分步沉淀。催化剂氧化态的IR结果表明了由3种沉淀方式所获得的样品中CuO和ZnO组分间相互作用的强弱。
Three copperbased catalysts(CuO/ZnO/Al2O3 )for methanol synthesis with the same Cu/Zn/Al atomic ratio (5∶4∶1) were prepared by normalprecipitation (that is addition of a solution of Na2CO3 to a mixed solution of Cu2+, Zn2+ and Al3+) , reverseprecipitation (addition of a mixed solution of Cu2+, Zn2+ and Al3+ to a solution of Na2CO3) and parallelflowprecipitation, respectively The activities of the catalysts indicate that the parallelflowprecipitation method is the best, and the reverseprecipitation method is also much better than the normalprecipitation method The order of reduction temperature from low to high obtained by TPR is as follows: reverseprecipitation catalysts<parallelflowprecipitation catalysts<normalprecipitation catalysts The DTA investigation of the catalyst precursors proved that by using reverseprecipitation or parallelprecipitation, Cu2+ and Zn2+ were precipitated simultaneously and uniformly, but, by using normalprecipitation, the phenomenon of Cu2+ and Zn2+ precipitation out of step had taken place The IR results of the three catalysts CuO/ZnO/Al2O3 indicate the change tendency of the interaction between CuO and ZnO with the precipitation method
出处
《天然气化工—C1化学与化工》
CAS
CSCD
北大核心
2003年第2期9-13,共5页
Natural Gas Chemical Industry
