Dehydra-decyclization of tetrahydrofurans to diene monomers over metal oxides,Catalysis Science & Technology

当前位置： X-MOL 学术 › Catal. Sci. Technol. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Dehydra-decyclization of tetrahydrofurans to diene monomers over metal oxides
Catalysis Science & Technology ( IF 4.4 ) Pub Date : 2020-07-24 , DOI: 10.1039/d0cy01117g
Yichen Ji _{1,

2,

3,

4} , Ajibola Lawal _{4,

5,

6,

7} , Andrew Nyholm _{1,

2,

3,

4} , Raymond J. Gorte _{1,

2,

3,

4,

8} , Omar A. Abdelrahman _{4,

5,

6,

7,

8}

Affiliation

The dehydra-decyclization of tetrahydrofuran (THF) to butadiene was investigated over a series of metal oxide catalysts, where a common set of chemical pathways was identified. Alongside butadiene, propene is formed via a retro-Prins condensation as the main side product typically observed. Reaction occurred at similar temperatures on each of the oxides, but tetragonal zirconia (t-ZrO₂) and monoclinic zirconia (m-ZrO₂) were unique in showing high selectivity to butadiene (>90%). Near quantitative yields to butadiene could be achieved over t-ZrO₂ at 673 K and a WHSV of 0.93 g THF gcat⁻¹ h⁻¹. Through contact time studies, butadiene is determined to be a primary product. Methyl-substituted THF gave only moderate increases in rates and the products showed minimal isomerization of the carbon backbone. The t-ZrO₂ catalyst was found to be relatively stable with time on stream, experiencing coking as a likely source of deactivation. Complete regeneration of the catalyst was demonstrated through calcination alone, allowing for multiple regenerations with no irreversible loss in activity or selectivity. The catalytic activity of zirconia was found to be structure insensitive, with t-ZrO₂ and m-ZrO₂ exhibiting similar initial activities; however, m-ZrO₂ was observed to deactivate much more rapidly.

中文翻译：

四氢呋喃在金属氧化物上的脱水脱环为二烯单体

在一系列金属氧化物催化剂上研究了四氢呋喃（THF）脱水脱水成丁二烯的过程，其中确定了一组常见的化学途径。与丁二烯一起，通过逆-普林斯缩合形成丙烯，这是通常观察到的主要副产物。每种氧化物在相似的温度下发生反应，但四方氧化锆（t-ZrO ₂）和单斜晶氧化锆（m-ZrO ₂）在显示出对丁二烯的高选择性（> 90％）方面是独特的。在673 K和0.93 g THF gcat ^-1 h ^-1的t-ZrO _2上，可以获得接近定量的丁二烯收率。通过接触时间研究，丁二烯被确定为主要产品。甲基取代的THF仅使速率适度增加，并且产物显示出碳骨架的最小异构化。发现t-ZrO ₂催化剂在生产过程中相对稳定，经历焦化是可能的失活来源。仅通过煅烧就证明了催化剂的完全再生，允许进行多次再生而活性或选择性没有不可逆转的损失。发现氧化锆的催化活性对结构不敏感，t-ZrO ₂和m-ZrO ₂表现出相似的初始活性。然而，观察到m-ZrO ₂失活更快。

更新日期：2020-09-05

点击分享查看原文

点击收藏

阅读更多本刊最新论文本刊介绍/投稿指南11