Aromatization mechanism of coupling reaction of light alkanes with CO over acidic zeolites: Cyclopentenones as key intermediates

芳构化 化学 选择性 光化学 烷烃 产量(工程) 反应机理 环戊烷 有机化学 催化作用 材料科学 冶金
作者
Changcheng Wei,Jinzhe Li,Kuo Yang,Qijun Yu,Shu Zeng,Zhongmin Liu
出处
期刊:Chem catalysis [Elsevier]
卷期号:1 (6): 1273-1290 被引量:26
标识
DOI:10.1016/j.checat.2021.09.004
摘要

The aromatization of light alkanes (C 4 -C 6 ) is an important value-added reaction. However, the yield of aromatics is always limited by the simultaneous generation of small alkanes (CH 4 and C 2 H 6 ) due to H/C balance. Herein, we demonstrate that the introduction of CO into light alkanes over zeolites significantly enhanced aromatic selectivity and an aromatics selectivity of 85% was achieved in the case of cyclopentane and CO coupling reaction over H-ZSM-5. Methyl-substituted cyclopentenones were observed and considered as the most important intermediates for aromatics formation. Multiple characterizations revealed the coupling mechanism: (1) CO inserts into carbenium ions to form acylium cations, (2) acylium cations react with olefins to generate unsaturated ketones, (3) unsaturated ketones cyclize to methyl-substituted cyclopentenones, (4) methyl-substituted cyclopentenones convert to monocytic aromatics. Methyl-substituted indanones were also discovered causing the generation of binuclear aromatics, such as naphthalene. Nano-sized ZSM-5 and TEOS modifications were applied to enhance the BTX selectivity. • High aromatic selectivity is achieved by coupling light alkanes with CO over H-ZSM-5 • Key intermediates are observed, and their formation and evolution route are clarified • The complete mechanism for coupling reaction of light alkanes with CO is proposed • Nano-sized ZSM-5 and TEOS modifications are applied to improve the BTX selectivity Light alkanes (C 4 -C 6 ) could be widely derived from refinery industry as byproducts, and the aromatization of light alkanes is an important value-added reaction. However, light alkanes had a higher hydrogen to carbon (H/C) ratio than that of aromatics from the perspective of element composition, so the yield of aromatics is always limited by the simultaneous generation of small alkanes (CH 4 and C 2 H 6 ) due to H/C balance requirement of the reaction. According to this, we expect that hydrogen-deficient substances, such as CO, are introduced into light alkane conversion to balance the excess hydrogen of alkanes. We indeed observe that the introduction of CO into light alkane over acidic zeolites could tune the H/C ratio of products and high aromatic selectivity could be achieved. Considering the large existing supply capacities of CO and light alkanes, the coupling reaction might have great potential for industrial applications. The introduction of CO into light alkanes over H-ZSM-5 significantly enhances aromatic formation, and high aromatics selectivity could be achieved. The key intermediates, such as methyl-substituted cyclopentenones and indanones, are observed on the reacted zeolites and could be converted into BTX and heavy aromatics, respectively. The formation and evolution route of these intermediates are clarified, and the coupling mechanism is proposed. According to this, using nano-size ZSM-5 and TEOS modifications significantly improves the BTX selectivity during the coupling reaction.
最长约 10秒,即可获得该文献文件

科研通智能强力驱动
Strongly Powered by AbleSci AI
更新
PDF的下载单位、IP信息已删除 (2025-6-4)

科研通是完全免费的文献互助平台,具备全网最快的应助速度,最高的求助完成率。 对每一个文献求助,科研通都将尽心尽力,给求助人一个满意的交代。
实时播报
淳于安筠发布了新的文献求助30
1秒前
柳叶洋完成签到,获得积分10
1秒前
下一秒发布了新的文献求助10
4秒前
5秒前
6秒前
无花果应助科研通管家采纳,获得10
6秒前
Akim应助科研通管家采纳,获得10
6秒前
852应助科研通管家采纳,获得10
6秒前
SYLH应助科研通管家采纳,获得30
6秒前
斯文败类应助科研通管家采纳,获得10
6秒前
Owen应助科研通管家采纳,获得10
6秒前
orixero应助科研通管家采纳,获得10
6秒前
Orange应助科研通管家采纳,获得10
6秒前
情怀应助科研通管家采纳,获得30
6秒前
Jasper应助科研通管家采纳,获得10
7秒前
英俊的铭应助科研通管家采纳,获得10
7秒前
7秒前
Ava应助科研通管家采纳,获得10
7秒前
情怀应助科研通管家采纳,获得10
7秒前
7秒前
7秒前
7秒前
7秒前
SYLH应助shensiang采纳,获得20
8秒前
专一的从波完成签到 ,获得积分10
8秒前
领导范儿应助msjs采纳,获得30
8秒前
量子星尘发布了新的文献求助10
10秒前
安静的幼旋完成签到,获得积分10
11秒前
11秒前
白石溪发布了新的文献求助10
11秒前
11秒前
loski发布了新的文献求助10
11秒前
13秒前
勤恳化蛹完成签到,获得积分10
13秒前
黄健斌发布了新的文献求助10
14秒前
15秒前
人生如梦应助2311采纳,获得10
16秒前
l璐w璐l完成签到,获得积分10
17秒前
ZY发布了新的文献求助10
18秒前
l璐w璐l发布了新的文献求助10
20秒前
高分求助中
A new approach to the extrapolation of accelerated life test data 1000
ACSM’s Guidelines for Exercise Testing and Prescription, 12th edition 500
‘Unruly’ Children: Historical Fieldnotes and Learning Morality in a Taiwan Village (New Departures in Anthropology) 400
Indomethacinのヒトにおける経皮吸収 400
Phylogenetic study of the order Polydesmida (Myriapoda: Diplopoda) 370
基于可调谐半导体激光吸收光谱技术泄漏气体检测系统的研究 350
Robot-supported joining of reinforcement textiles with one-sided sewing heads 320
热门求助领域 (近24小时)
化学 材料科学 医学 生物 工程类 有机化学 生物化学 物理 内科学 纳米技术 计算机科学 化学工程 复合材料 遗传学 基因 物理化学 催化作用 冶金 细胞生物学 免疫学
热门帖子
关注 科研通微信公众号,转发送积分 3989444
求助须知:如何正确求助?哪些是违规求助? 3531531
关于积分的说明 11254250
捐赠科研通 3270191
什么是DOI,文献DOI怎么找? 1804901
邀请新用户注册赠送积分活动 882105
科研通“疑难数据库(出版商)”最低求助积分说明 809174