NH_4F改性ZSM-5用于甲醇制丙烯反应
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- 英文论文题名：NH4F modified ZSM-5 for methanol-to-propylene reaction
- 论文作者：李珊珊 ; 刘民 ; 郭新闻 ; 宋春山
- 英文论文作者：Shanshan Li ; Min Liu ; Xinwen Guo ; Chunshan Song
- 年：2016
- 作者机构：大连理工大学精细化工国家重点实验室化工学院催化化学与工程系;宾夕法尼亚州立大学能源研究所能源与矿物工程系;
- 论文关键词：NH4F处理 ; 酸强度 ; 被打乱的四配位Al ; MTP
- 会议召开时间：2016-07-01
- 会议录名称：中国化学会第30届学术年会摘要集-第三十二分会： 多孔功能材料
- 语种：中文
- 分类号：TQ221.212;O643.36
- 学会代码：ZGHY
- 会议名称：中国化学会第30届学术年会-第三十二分会 ; 多孔功能材料
- 会议地点：中国辽宁大连
- 主办单位：中国化学会
- 学会名称：中国化学会
- 页数：1
- 文件大小：223k
- 原文格式：D
- 会议级别：全国
摘要
甲醇制丙烯反应的常用催化剂为ZSM-5分子筛,然而其较强的酸性导致催化剂的寿命短和丙烯选择性低。NH_4F改性可以修饰骨架Al,使其变为被打乱的四配位骨架Al,这种Al既不是强酸位也不是弱酸位,~1而通常的水热处理之后骨架Al变为非骨架Al,需要额外的一步酸洗才能彻底脱出这些非骨架Al。同时NH_4F处理之后还可以移除缺陷,而缺陷也是催化剂稳定性差的一个原因。~2随着NH_4F浓度的增加,酸量和酸强度呈明显的降低趋势。将不同浓度NH_4F处理的催化剂用于甲醇制丙烯反应,随着NH_4F浓度的增加,催化剂的寿命延长,当NH_4F浓度增加到0.078M时,催化剂的寿命达到最大。进一步增加NH_4F浓度,催化剂的酸量不足以维持反应所需,催化剂的寿命降低。因此采用0.078M NH_4F处理的催化剂具有最适宜的酸量和酸强度,能够达到最优MTP反应性能。
ZSM-5 which has strong acid sites is usually served as preferable catalyst for methanol to propylene reaction.However it still showed not very good propylene selectivity and stability because of stronger acid strength.A distinctive Al which determined as distorted framework Al was received by NH_4F treatment,and it contributes less to weak and strong acid sites.Thus this simple treatment would replace sequential hydrothermal treatment and acid washing.Acid strength and amount gradually decrease as higher concentration of NH_4F.HZSM-5 treated by NH_4F of different concentrations were used as MTP reaction catalysts,catalysts life shows vocalnic type as different concentrations of NH_4F treatment,when the NH_4F concentrations reached to 0.078 M,the catalyst shows maximal lifetime.There have been less acid sites for MTP reaction with further increase of NH_4F concentration.Therefore,0.078 M NH_4F treated catalyst has the optimum amount of acid amount and strength,it can achieve optimal MTP reaction performance.
ZSM-5 which has strong acid sites is usually served as preferable catalyst for methanol to propylene reaction.However it still showed not very good propylene selectivity and stability because of stronger acid strength.A distinctive Al which determined as distorted framework Al was received by NH_4F treatment,and it contributes less to weak and strong acid sites.Thus this simple treatment would replace sequential hydrothermal treatment and acid washing.Acid strength and amount gradually decrease as higher concentration of NH_4F.HZSM-5 treated by NH_4F of different concentrations were used as MTP reaction catalysts,catalysts life shows vocalnic type as different concentrations of NH_4F treatment,when the NH_4F concentrations reached to 0.078 M,the catalyst shows maximal lifetime.There have been less acid sites for MTP reaction with further increase of NH_4F concentration.Therefore,0.078 M NH_4F treated catalyst has the optimum amount of acid amount and strength,it can achieve optimal MTP reaction performance.
引文
[1]T.Xu,Q.Zhang,H.Song and Y.Wang,J.Catal.,2012,295,232-241.
[2]P.Sazama,B.Wichterlova,Microporous Mesoporous Mater.,2011,143,87-96.
[2]P.Sazama,B.Wichterlova,Microporous Mesoporous Mater.,2011,143,87-96.