简单的H2O-贡献的O2激活策略超过基于Mn的SCR催化剂,以抵消SO2中毒
Dongqi An1, Jiawei Ji1, Qianni Cheng1
1China State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Jiangsu Key Laboratory of Vehicle Emissions Control, Center of Modern Analysis, Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P. R. China.
Environmental science & technology
|September 22, 2023
概括
令人惊的是,水通过抵消二氧化硫 (SO2) 中毒,帮助催化剂进行选择性催化还原 (SCR). 这项研究揭示了水如何增强氧气激活,产生用于催化剂再生的活性氧物种 (ROS).
科学领域:
- 催化剂是一种催化剂.
- 环境化学环境化学
- 材料科学 材料科学 材料科学
背景情况:
- 基于的催化剂对于低温选择性催化还原 (SCR) 至关重要,但易受二氧化硫 (SO2) 毒害的影响.
- SO2中毒导致硫酸盐的形成,阻碍氧气的激活,减少SCR反应所必需的活性氧物种 (ROS).
- 传统上,水 (H2O) 被视为有害物质,在存在SO2的情况下加剧催化剂失活.
研究的目的:
- 调查水在减轻基SCR催化剂中SO2中毒的反直觉作用.
- 阐明水增强氧气激活和ROS生成的机制.
- 为了证明在SO2暴露下使用水进行催化剂再生的潜力.
主要方法:
- 在模拟SO2和H2O暴露的条件下对Mn基催化剂 (特别是γ-MnO2) 的实验研究.
- 对氧激活通路和反应性氧物种 (ROS) 生成的分析.
- 通过温和热处理评估催化剂性能和再生效率.
主要成果:
- 水协同激活氧气,产生ROS,抵消SO2诱导的失活.
- 水引起的激活能量 (Ea) 减少有助于ROS的形成和活性.
- 在SO2+H2O暴露和轻度热处理后,γ-MnO2催化剂显示其NO去除能力的完全再生.
- 观察到的机制适用于各种基于Mn的SCR催化剂.
结论:
- 水在基于Mn的SCR催化剂中起着有益的作用,积极抵消SO2中毒.
- O2和H2O的协同激活产生ROS,这是催化剂再生的关键.
- 这种以水为辅助的策略提供了一种有前途的方法,用于提高基于的SCR催化剂在污染环境中的耐用性和性能.
相关概念视频
Catalysis
27.0K
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.
27.0K
Radical Oxidation of Allylic and Benzylic Alcohols
2.0K
Activated manganese(IV) oxide can selectively oxidize allylic and benzylic alcohols via a radical intermediate mechanism. Primary allylic alcohols are oxidized to aldehydes, while secondary allylic alcohols yield ketones. The redox reaction of potassium permanganate with an Mn(II) salt such as manganese sulfate (under either alkaline or acidic conditions), followed by thorough drying, yields the oxidizing agent: activated MnO2. While MnO2 is insoluble in the solvents used for the reaction, the...
2.0K
Bioremediation
18.8K
Bioremediation is the use of prokaryotes, fungi, or plants to remove pollutants from the environment. This process has been used to remove harmful toxins in groundwater as a byproduct of agricultural run-off and also to clean up oil spills.
18.8K
Limiting Reactant
59.1K
The relative amounts of reactants and products represented in a balanced chemical equation are often referred to as stoichiometric amounts. However, in reality, the reactants are not always present in the stoichiometric amounts indicated by the balanced equation.
59.1K
Preparation and Reactions of Thiols
6.3K
Thiols are prepared using the hydrosulfide anion as a nucleophile in a nucleophilic substitution reaction with alkyl halides. For instance, bromobutane reacts with sodium hydrosulfide to give butanethiol.
6.3K
Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
18.2K
Introduction
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
18.2K


