相关实验视频
Updated: May 10, 2025

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Electrochemically and Bioelectrochemically Induced Ammonium Recovery
Published on: January 22, 2015
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通过无金属双原子合并进行三重协同工程,用于自维持的酸性氨电合成
Chuanzhen Feng1, Kaiwen Bo1, Jin Wan1
1The School of Chemistry and Chemical Engineering, National Key Laboratory of Power Transmission Equipment Technology, Chongqing University, 174 Shazheng Street, Shapingba District, Chongqing, 400044, P.R. China.
Angewandte Chemie (International ed. in English)
|April 28, 2025
概括
一种新的无金属催化剂在酸性条件下有效地将酸盐转化为氨,克服了可持续化肥生产的稳定性和选择性挑战.
科学领域:
- 材料科学 材料科学 材料科学
- 电化学 电化学 电化学
- 催化剂是一种催化剂.
背景情况:
- 对氨的电化学酸盐还原反应 (NO3RR) 为肥料生产提供了优势,但也面临着挑战.
- 现有的金属催化剂遭受不稳定性,进化反应 (HER) 竞争,和质子耗尽.
- 酸性条件对于直接合成氨和防止挥发是可取的.
研究的目的:
- 开发一种新的无金属催化剂,用于在酸性介质中有效和稳定的电化学酸盐降解.
- 解决催化剂不稳定性,HER竞争和质子/物种不平衡问题.
- 阐明原子级三重协同机制,以提高NO3RR性能.
主要方法:
- 使用渐变加热共载制造-双原子催化剂,安装在氧化超薄纳米片 (Si/I-NiO@CC) 上.
- 电化学表征,包括法拉戴在酸性电解质中的效率和稳定性测试.
- 在现场进行光谱分析,以调查催化机制和活性位点.
主要成果:
- 在NO3RR下达到96.8%的Faradaic效率,在-0.3V和RHE之间达到创纪录的效率.
- 经过420小时的特殊运行稳定性,超过了所有报告的酸NO3RR电催化剂.
- 确定了一种三重协同机制,涉及缺电子的Ni,氧空缺,介导的质子储库和Si-O-Ni界面键.
结论:
- 开发的无金属Si/I-NiO@CC催化剂有效地克服了酸性NO3RR中的关键挑战.
- 原子级三重协同工程为高效和稳定的氨合成提供了可行的策略.
- 这项工作为设计用于选择性酸盐减少的先进电催化剂提供了建设性的指导方针.
相关概念视频
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The acidic strength of hydrocarbons follows the order: Alkynes > Alkenes > Alkanes. The strength of an acid is commonly expressed in units of pKa — the lower the pKa, the stronger the acid. Among the hydrocarbons, terminal alkynes have lower pKa values and are, therefore, more acidic. For example, the pKa values for ethane, ethene, and acetylene are 51, 44, and 25, respectively, as shown here.
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Strong bases like NaOH or KOH deprotonate the phthalimide to form the corresponding anion, which acts as a nucleophile. Further, the anion attacks an...
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In the first step of the aminolysis mechanism, the amine attacks the carbonyl carbon of the acyl chloride to form a tetrahedral intermediate. In the second step, the carbonyl group is re-formed with the elimination of a chloride...
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Preparation of Amines: Alkylation of Ammonia and Amines
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Alkylation is one of the methods used to prepare amines. Direct alkylation of ammonia or a primary amine with an alkyl halide gives polyalkylated amines along with a quaternary ammonium salt through successive SN2 reactions. This process of making the quaternary salt through the direct alkylation method is called exhaustive alkylation.
Each alkylation step makes the nitrogen center more nucleophilic, which triggers successive alkylations until a quaternary ammonium salt is formed. Considering...
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Reduction of Alkynes to trans-Alkenes: Sodium in Liquid Ammonia
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Alkynes can be reduced to trans-alkenes using sodium or lithium in liquid ammonia. The reaction, known as dissolving metal reduction, proceeds with an anti addition of hydrogen across the carbon–carbon triple bond to form the trans product. Since ammonia exists as a gas (bp = −33°C) at room temperature, the reaction is carried out at low temperatures using a mixture of dry ice (sublimes at −78°C) and acetone.
When dissolved in liquid ammonia, an alkali metal,...
When dissolved in liquid ammonia, an alkali metal,...
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Aldehydes and Ketones with Amines: Imine Formation Mechanism
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Imine formation involves the addition of carbonyl compounds to a primary amine. It begins with the generation of carbinolamine through a series of steps involving an initial nucleophilic attack and then several proton transfer reactions. The second part includes the elimination of water, as a leaving group, to give the imine.
Imines are formed under mildly acidic conditions. A pH of 4.5 is ideal for the reaction.
If the pH is low or the solution is too acidic, the reaction slows down in the...
Imines are formed under mildly acidic conditions. A pH of 4.5 is ideal for the reaction.
If the pH is low or the solution is too acidic, the reaction slows down in the...
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