使用Pd-化物形成的内在外热性来触发林模型化合物烯乙烯的解
Erin V Phillips1, Marta C Hatzell2,3, Carsten Sievers1,3
1School of Chemistry and Biochemistry and School of Chemical and Biomolecular Engineering, Georgia Institute of Technology Atlanta Georgia 30332 USA carsten.sievers@chbe.gatech.edu.
概括
从支持的催化剂中形成化 (Pd-H) 的外热形成释放热量,在没有外部加热的情况下启动 phenyl 以太 (BPE) 的裂变. 这种催化过程为素模型化合物解提供了一条新的途径.
科学领域:
- 催化剂是一种催化剂.
- 材料科学 材料科学 材料科学
- 化学工程是化学工程的重要组成部分.
背景情况:
- phenyl 以太 (BPE) 是一个素模型化合物,代表α-O-4 以太链接.
- 催化解是生物质转化的一个关键过程.
- (Pd) 催化剂在化反应中被广泛使用.
研究的目的:
- 为了研究使用外热化化形成作为BPE解的启动剂.
- 探索不同催化剂对反应支的影响.
- 了解热流,催化剂特性和BPE转换之间的关系.
主要方法:
- 准备并进行了支持催化剂 (Pd/C,Pd/SiO2,Pd/Al2O3) 的表征.
- 反应是在名义上的环境条件下进行的,暴露在气中.
- 热重力测量分析与差分扫描热量计 (TGA-DSC) 结合使用,以测量热流.
- 通过X射线吸收光谱 (XAS) 证实了Pd-化物形成.
- 量化了BPE转换的情况.
主要成果:
- 自发和外热的Pd-化物形成释放出显著的热量 (分别为Pd/C,Pd/SiO2和Pd/Al2O3的58,40和32Wg-1).
- 这种内在的热量启动了BPE的α-O-4以太裂变,而无需外部加热.
- BPE转换与热流,较高的Pd粒子分散和较低的支热容量正相关.
- XAS证实了化物种的形成.
结论:
- 在外热Pd-化物形成过程中产生的热量可以有效地启动BPE的解,这是一种固体素模型化合物.
- 催化剂支特性显著影响反应的外热度和效率.
- 这种自我加热的催化方法为生物质的价值化和木质素的脱聚合提供了一个有希望的替代方案.
相关概念视频
Hydrolysis of Chlorobenzene to Phenol: Dow Process
3.9K
Simple aryl halides do not react with nucleophiles under normal conditions. However, the reaction can proceed under drastic conditions involving high temperatures and high pressure to give the substituted products. For example, chlorobenzene is converted to phenol using aqueous sodium hydroxide at 350 °C under high pressure by the Dow process. The reaction follows an elimination-addition mechanism involving a benzyne intermediate. Here, the chloride ion is...
3.9K
Reduction of Benzene to Cyclohexane: Catalytic Hydrogenation
5.7K
Unlike the easy catalytic hydrogenation of an alkene double bond, hydrogenation of a benzene double bond under similar reaction conditions does not take place easily. For example, in the reduction of stilbene, the benzene ring remains unaffected while the alkene bond gets reduced. Hydrogenation of an alkene double bond is exothermic and a favorable process. In contrast, to hydrogenate the first unsaturated bond of benzene, an energy input is needed; that is, the process is endothermic. This is...
5.7K
Radical Substitution: Hydrogenolysis of Alkyl Halides with Tributyltin Hydride
2.2K
Radical substitution reactions can be used to remove functional groups from molecules. The hydrogenolysis of alkyl halides is one such reaction, where the weak Sn–H bond in tributyltin hydride reacts with alkyl halides to form alkanes. Here, the reagent Bu3SnH yields tributyltin halide as a byproduct.
The bonds formed in this reaction are stronger than the bonds broken, making it energetically favorable. The reaction follows a radical chain mechanism similar to radical halogenation reactions,...
The bonds formed in this reaction are stronger than the bonds broken, making it energetically favorable. The reaction follows a radical chain mechanism similar to radical halogenation reactions,...
2.2K
Radical Formation: Homolysis
4.2K
A bond is formed between two atoms by sharing two electrons. When this bond is broken by supplying sufficient energy, either two electrons can be taken up by one atom forming ions by the cleavage called heterolysis, or the two electrons are shared by two atoms, with one each creating radicals by the cleavage called homolysis.
4.2K
Electrophilic 1,2- and 1,4-Addition of HX to 1,3-Butadiene
7.6K
The electrophilic addition of hydrogen halides such as HBr to alkenes and nonconjugated dienes gives a single product as per Markovnikov’s rule.
7.6K
Benzene to 1,4-Cyclohexadiene: Birch Reduction Mechanism
2.6K
Birch reduction uses solvated electrons as reducing agents. The reaction converts benzene to 1,4-cyclohexadiene. The reaction proceeds by the transfer of a single electron to the ring to form a benzene radical anion. This anion is highly basic—it abstracts a proton from the alcohol to form a cyclohexadienyl radical. Another single electron transfer gives the cyclohexadienyl anion. A proton transfer from the alcohol forms 1,4-cyclohexadiene. Since this reduction occurs via radical anion...
2.6K


