摘要
研究了在纯氢气下 Al,Mn,Sm,Th 等元素和在氮氢混合气下 Y,Nd 等稀土元素对Cu—Fe 系加氢制备高碳醇催化剂活性的影响.结果表明,添加剂可以提高 Cu-Fe 系催化剂在纯氢气下的加氢活性,可以改善其在氮氢混合气下的加氢性能。在纯氢气下,Mn 以 Mn(CH_3COO)_2的形式加入,经和主体元素共沉淀及焙烧后,以 MnO_2形式存在,当 MnO_2含量为5%时,高碳醇得率可由53.7%提高到57.5%;当 MnO_2含量为10%时,高碳醇得率可提高到66.4%。因此,Mn 是很好的添加剂,其次是 Al,但直接添加 Al_2O_3,不如添加 Al 盐[Al_2(SO_4)_3·18H_2O]效果好.此外,添加 Sm_2O_3 1%和 ThO_21%[以 Th(NO_3)_4形式加入]可使高碳醇收率提高3%左右.在氮氢混合气(N_2:H_2=1:3)下,Cu—Fe 催化剂活性则大幅度下降,高碳醇得率由53.7%下降到23.1%;而添加稀土元素的 Cu—Fe 系催化剂则可阻止其活性下降,甚至提高其活性.添加 Nd_2O_31%,高碳醇得率由53.7%下降到52.1%,而添加 Y_2O_31%,高碳醇得率反而由53.7%上升到56.1%,进一步研究指出,添加剂对 Cu—Fe 系催化剂活性的影响与添加剂的磁性,吸附氢的性质等因素有关。
The effects of additives,Mn Al Sm Th Y and Nd,on activity of Cu—Fe catalyst have been studied in pure hydrogen and in the mixture of nitrogen and hydrogen, respectively.The results show that Mn is an excelent additive in pure hydrogen.When Mn is added in the form of Mn(CH_3COO)_2,it exists in the form of MnO_2 after coprecipita- tion and calcination.The yield of fatty alcohols increases to 57.5% and 66.4% from 53. 7% for 5% and 10% MnO_1 contents,respectively.Al is also an effective promoter and Al_2 (SO_4)_3 as precursor is better than Al_2O_3.When 1% rare earth oxide,Sm_2O_3 or ThO_2 is added,the yield increases about 3%.If the mixture of nitrogen and hydrogen is used,the yield of ratty alcohols decreases to 23.1% from 53.7% for Cu—Fe catalyst.However,it is found that rare earth oxide could resist the activity decrease even increase its activity. For instance,1%~ Nd_2O_3,the yield decreases only to 52.1%,while 1%Y_2O_3,it increases to 56.1%.The reason that these promoters affect the yield of fatty alcohols is also dis- cussed.
出处
《郑州大学学报（自然科学版）》
CAS
1997年第2期82-87,共6页
Journal of Zhengzhou University (Natural Science)
基金
河南省自然科学基金
关键词
添加剂
活性
铜铁系催化剂
评价
additives
Cu—Fe catalyst
rare earth oxides
activity
