一个有机质子子,它对氧化物促进的降解具有极强的抗性
Chase L Radford1, Torben Saatkamp1, Andrew J Bennet2
1Department of Chemistry, Simon Fraser University, Burnaby, Canada.
Nature communications
|April 22, 2024
概括
一个新的阴离子质子,1,6-diazabicyclo[4.4.4]tetradecan-1,6-ion (in-DBD),在性条件下显示出优越的稳定性. 这一突破使燃料电池等电化学设备的耐用离子交换膜成为可能.
科学领域:
- 电化学 电化学 电化学
- 材料科学 材料科学 材料科学
- 聚合物化学 聚合物化学
背景情况:
- 性聚合物膜电化学装置为非白金组催化剂提供了潜力.
- 由于降解问题,当前的有机酸对于蒸汽相应用 (如燃料电池) 缺乏稳定性.
研究的目的:
- 为性电化学设备开发一种具有增强稳定的新型有机阴离子.
- 为了研究在恶劣的性条件下1,6-diazabicyclo[4.4.4]tetradecan-1,6-ion (in-DBD) 的稳定性.
主要方法:
- 1,6-diazabicyclo[4.4.4]tetradecan-1,6-ion (in-DBD) 电离子的合成和表征.
- 在超干燥条件和高温下评估氧化物促进的降解耐受性.
- 在临界低水分水平 (在80°C下<10%的RH) 上评估阴离子稳定性.
主要成果:
- 与最先进的有机离子相比,DBD中的离子对氧化物促进的降解具有数量级更高的抵抗力.
- in-DBD是第一个在<10%的RH和80°C下保持稳定的有机氧化.
- 增强的稳定性归因于内体保护和桥头内部的键,防止了质子去除和霍夫曼消除.
结论:
- 在DBD中的阴离子代表了性电化学设备的材料稳定性的显著进步.
- 这一发现有望在极端性条件下使离子交换膜能够稳定运行.
- 促进下一代燃料电池和其他电化学能量转换装置的开发.
相关概念视频
03:38Polyprotic Acids
29.1K
Acids are classified by the number of protons per molecule that they can give up in a reaction. Acids such as HCl, HNO3, and HCN that contain one ionizable hydrogen atom in each molecule are called monoprotic acids. Their reactions with water are:
29.1K
02:29Relative Strengths of Conjugate Acid-Base Pairs
45.7K
Brønsted-Lowry acid-base chemistry is the transfer of protons; thus, logic suggests a relation between the relative strengths of conjugate acid-base pairs. The strength of an acid or base is quantified in its ionization constant, Ka or Kb, which represents the extent of the acid or base ionization reaction. For the conjugate acid-base pair HA / A−, the ionization equilibrium equations and ionization constant expressions are
45.7K
01:18Titration of Polyprotic Base with a Strong Acid
791
The titration of a polyprotic base such as sodium carbonate with a strong acid such as hydrochloric acid results in two equivalence points on the titration curve. At the first equivalence point, the carbonate ions in the base are completely converted to bicarbonate ions. The second equivalence point corresponds to the complete conversion of bicarbonate ions to carbonic acid, which dissociates into carbon dioxide and water. The region before the first equivalence point corresponds to the...
791
01:01Acid Halides to Carboxylic Acids: Hydrolysis
2.6K
Hydrolysis of acid halides is a nucleophilic acyl substitution reaction in which acid halides react with water to give carboxylic acids. The reaction occurs readily and does not require acid or a base catalyst.
As shown below, the mechanism involves a nucleophilic attack by water at the carbonyl carbon to form a tetrahedral intermediate. This is followed by the reformation of the carbon–oxygen π bond along with the departure of a halide ion. A final proton transfer step yields carboxylic...
As shown below, the mechanism involves a nucleophilic attack by water at the carbonyl carbon to form a tetrahedral intermediate. This is followed by the reformation of the carbon–oxygen π bond along with the departure of a halide ion. A final proton transfer step yields carboxylic...
2.6K
02:08Titration of a Polyprotic Acid
96.5K
A polyprotic acid contains more than one ionizable hydrogen and undergoes a stepwise ionization process. If the acid dissociation constants of the ionizable protons differ sufficiently from each other, then the titration curve for such polyprotic acid generates a distinct equivalence point for each of its ionizable hydrogens. Therefore, titration of a diprotic acid results in the formation of two equivalence points, whereas the titration of a triprotic acid results in the formation of three...
96.5K
02:54Ions as Acids and Bases
23.7K
Salts with Acidic Ions
Salts are ionic compounds composed of cations and anions, either of which may be capable of undergoing an acid or base ionization reaction with water. Aqueous salt solutions, therefore, may be acidic, basic, or neutral, depending on the relative acid-base strengths of the salt’s constituent ions. For example, dissolving the ammonium chloride in water results in its dissociation, as described by the equation:
Salts are ionic compounds composed of cations and anions, either of which may be capable of undergoing an acid or base ionization reaction with water. Aqueous salt solutions, therefore, may be acidic, basic, or neutral, depending on the relative acid-base strengths of the salt’s constituent ions. For example, dissolving the ammonium chloride in water results in its dissociation, as described by the equation:
23.7K