摘要
用Ｘ射线衍射、小角Ｘ射线散射、ＢＥＴ流动色谱及化学分析等方法，对工业甲醇合成催化剂在失活前后的物相、晶粒度、孔径分布和比表面积等物化性质进行测定。与新鲜催化剂对比后发现，失活催化剂有硫中毒现象。在ＨＣｌ＋Ｈ２Ｏ２的混合溶液不溶物残渣中，有Ｃ和ＡｌＶ２Ｏ４晶相出现，且残渣的含量增多。氧化态时，催化剂的孔径主要分布在ｄ≤１０ｎｍ的微孔区，在经过Ｈ２还原后，孔径分布发生变化，有相当部分转变为ｄ＞１０ｎｍ的过渡孔。晶粒度测定结果表明，催化剂中Ｃｕ（１１１）晶面的平均线宽约为２７ｎｍ，在失活前后变化不大；而ＺｎＯ（１１０）晶面的平均线宽在失活后有显著长大，从８．９ｎｍ变为１５．８ｎｍ。对催化剂的失活原因进行了分析。
The physical and Chemical properties,such as phase composition,crystal size,pore size distribution,and surface area,of the copper based catalyst for methanol synthesis are investigated before and after deactivation of the catalyst by using X ray diffraction(XRD) and small angular X ray scatting(SAXS) techniques, BET method ,and chemical analysis. The results show that the contents of Cu and Zn components are reduced more or less and a Cu 2S phase is found in the deactivated catalyst;the insoluble substances, mainly C and AlV 2O 4,in the mixed HCI+H 2O 2 solution are found to have increased.At the oxide state,the pore sizes are mainly distributed in the regime of d ≤10nm.There is a significant change in pore size distribution after reduction with H 2, and part of the fine pores is transformed into mediate pores of d >10nm. The results of crystal size determination show that an average crystal size of the Cu(111) crystal surface is about 27nm,not varying much before and after deactivation of the catalyst;but the average crystal size of the ZnO(110) remarkably increases from 8.9 nm to 15.8nm after deactivation.It is also discussed that the catalyst is deactivated due to the growth of ZnO crystal size,sulphide poisoning,and coke deposition.
出处
《天然气化工—C1化学与化工》
CAS
CSCD
北大核心
1997年第4期5-9,共5页
Natural Gas Chemical Industry
关键词
甲醇合成
铜基催化剂
失活
铜催化剂
methanol synthesis,deactivation,copper based catalyst
