通过同时调节三种替代效应来增强分子电催化剂的CO2减少活性
Weixuan Nie1, Drew E Tarnopol1, Charles C L McCrory1,2
1Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States.
Journal of the American Chemical Society
|March 8, 2021
概括
研究人员通过整合配体替代效应,使用复合物增强了二氧化碳 (CO2) 的减少. 这一策略显著提高了二氧化碳转化为有价值产品的催化活性和效率.
科学领域:
- 无机化学
- 催化剂
- 电化学
背景情况:
- 开发高效的二氧化碳减排分子催化剂 (CO2RR) 对可持续化学至关重要.
- 复合物与二胺配体已经显示出有前途,但需要进一步增强活性.
- 了解替代剂对联体设计的影响是优化催化剂性能的关键.
研究的目的:
- 研究扩展结合的协同效应,电子吸收能力和分子内静电效应对基于的二氧化碳还原催化剂.
- 设计和合成新的复合物与量身定制的二胺配体.
- 将结构修改与减少二氧化碳的电催化性能相关联.
主要方法:
- 一系列含有系统变化的替代剂的化合物的合成和表征.
- 电化学评估使用循环电压测量和时测量来确定催化活性,发作潜力和法拉第效率.
- 用光谱分析来了解复合物的电子和结构性质.
主要成果:
- 一系列的复合体显示了二氧化碳减排的逆缩放关系,随着联体电子效应的出现,活动增加.
- 复合物[Co(PDI-PyCH3+I-) 的二氧化碳减排活动显著增强,达到4.1×10^4s^-1的转换频率.
- 这种优化的催化剂具有更积极的催化启动电位 (Eonset = -1.52 V vs Fc+/0) 和高于95%的法拉第效率.
结论:
- 在二胺配体中同时整合扩展的结合,提取电子的能力和分子内静电效应显著增强了复合物的电催化活性以减少二氧化碳.
- 开发的催化剂[Co(PDI-PyCH3+I-) 是CO2RR报告中最活跃的分子催化剂之一,在特定条件下有效运行.
- 本研究提出了一种可行的催化剂设计策略,通过调整协同替代效应来制造高活性分子二氧化碳减排催化剂.
更多相关视频
相关概念视频
Introduction to Mechanisms of Enzyme Catalysis
9.8K
For many years, scientists thought that enzyme-substrate binding took place in a simple "lock-and-key" fashion. This model stated that the enzyme and substrate fit together perfectly in one instantaneous step. However, current research supports a more refined view scientists call induced fit. The induced-fit model expands upon the lock-and-key model by describing a more dynamic interaction between enzyme and substrate. As the enzyme and substrate come together, their interaction causes...
9.8K
Carbocations
12.6K
Carbocations are one of the reaction intermediates formed during several nucleophilic substitutions or elimination reactions. A carbocation is an electron-deficient species with the central carbon atom having six electrons and three bonded atoms. The central carbon in a carbocation is sp2 hybridized with trigonal planar geometry. It has an empty p orbital perpendicular to the plane of the structure that can accept electrons. Thus, carbocations act as strong electrophiles and may react with any...
12.6K
meta-Directing Deactivators: –NO2, –CN, –CHO, –⁠CO2R, –COR, –CO2H
6.2K
All meta-directing substituents are deactivating groups. These substituents withdraw electrons from the aromatic ring, making the ring less reactive toward electrophilic substitution. For example, the nitration of nitrobenzene is 100,000 times slower than that of benzene because of the deactivating effect of the nitro group. The first step in an electrophilic aromatic substitution is the addition of an electrophile to form a resonance-stabilized carbocation. The energy diagrams for...
6.2K
Regioselectivity of Electrophilic Additions-Peroxide Effect
9.5K
In the presence of organic peroxides, the addition of hydrogen bromide to an alkene yields the isomer that is not predicted by Markovnikov’s rule. For example, the addition of hydrogen bromide to 2-methylpropene in the presence of peroxides gives 1-bromo-2-methylpropane. This addition reaction proceeds via a free radical mechanism, which reverses the regioselectivity. The free radical reaction mechanism involves three stages: initiation, propagation, and termination.
9.5K
Catalysis
28.9K
The presence of a catalyst affects the rate of a chemical reaction. A catalyst is a substance that can increase the reaction rate without being consumed during the process. A basic comprehension of a catalysts’ role during chemical reactions can be understood from the concept of reaction mechanisms and energy diagrams.
28.9K
Thermal and Photochemical Electrocyclic Reactions: Overview
2.7K
Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.
2.7K


