Development of Environmental Catalytic Reactors Based on Electrochemical Acceleration

基于电化学加速的环保催化反应器的研制

• 批准号: 17360391
• 负责人: MACHIDA Masato
• 金额: $ 10.63万
• 依托单位: Kumamoto University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2005
• 资助国家: 日本
• 起止时间: 2005 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-17360391/
• 关键词: nitrate ions; electrochemical reactor; nitrogen oxide; drinking water; solid electrolyte; Nafion; 電極触媒; 飲料水; 硝酸イオン還元; 高分子固体電解質; 浄水; 電極; プロトン伝導体; 硝酸性窒素; 水素; 電気化学

The reduction of NO_x, in the presence of excess O_2 has been successfully achieved at 70℃ using an electrochemical cell. An H+-conducting solid polymer electrolyte(SPE)yielded hydrogen on the Pt cathode to ca+C476use the catalytic NO-H_2 reaction. It was revealed that the electrochemically evolved hydrogen on the Pt cathode is more active toward NO than molecular H_2 in the gas feed. The competitive H_2-O_2 reaction is suppressed because the Pt surface is covered with stable nitrate(NO_3)species, which blocks oxygen adsorption hereon. The combination between the SPE cell and supported Pt catalysts can broadly be applied to novel low-temperature de-NO_x processes. Electrocatalytic reduction of nitrate ions(NO_3)was also carried out over Cu-Pd and Cu-Pt bimetallic cathodes, which were deposited on a Nafion-117 H^+-conducting polymer membrane. By applying DC current to the membrane-electrode assembly(MEA), H_2 evolved on the cathode caused monotonic degradation of NO_3^- in the cathode compartment. The. NO_3^- reduction proceeded in a consecutive manner and copper increased significantly the catalytic activity for the first step from NO_3^- to NO_2^-. The Cu-Pd and Cu-Pt cathodes, having 38 and 20 at% Cu, respectively, exhibited the highest reduction rate. The product selectivity was also dependant on the content of Cu. The Cu-Pd cathode showed a lower selectivity to NO_2^- and a higher selectivity to NH_4^+, because the catalytic activity for NO_2 reduction is high. The rate of nitrate reduction was increased by supplying CO_2, which plays a role of a buffer to keep pH lower than 7 and shift the equilibrium of the reaction, 2NO_3 + 5H_2 + N_2 + 2OH^- + 4H_2O.

在过量O_2存在下，使用电化学电池在70℃下成功实现了NO_x的还原，H+导电固体聚合物电解质(SPE)在Pt阴极上通过催化NO-H_2反应产生氢气到ca+C476。结果表明，Pt 阴极上电化学析出的氢对 NO 的活性比气体进料中的分子 H_2 更具竞争性。由于Pt表面覆盖有稳定的硝酸盐(NO_3)物质，阻碍了氧的吸附，因此H_2-O_2反应受到抑制。固相萃取池与负载型Pt催化剂的结合可广泛应用于新型低温脱NO_x过程。还在Cu-Pd和Cu-Pt双金属阴极上进行了硝酸根离子(NO_3)的电催化还原，这些阴极沉积在Nafion-117 H^+-导电聚合物膜通过向膜电极组件(MEA)施加直流电流，在阴极上释放出H_2，导致阴极室中NO_3^-的单调降解。连续的方式和铜显着增加了从NO_3^-到NO_2^-的第一步的催化活性，具有Cu-Pd和Cu-Pt阴极。 38和20 at% Cu分别表现出最高的还原率。产物选择性还取决于Cu的含量。Cu-Pd阴极对NO_2^-表现出较低的选择性，而对NH_4^+表现出较高的选择性。 NO_2还原的催化活性高，通过提供CO_2提高硝酸盐还原速率，CO_2起到缓冲作用，使pH值低于7并移动反应平衡。 2NO_3 + 5H_2 + N_2 + 2OH^- + 4H_2O。

项目成果

Selective Electrocatalytic Reduction of NO_3- and NO_2- Ions by Ternary Metal-Solid Polymer Electrolyte Assemblies

三元金属-固体聚合物电解质组件选择性电催化还原NO_3-和NO_2-离子

• 发表时间: 2007
• 作者: M.A.Hasnat

Low-temperature Electrocatalytic NOx Reduction Using Solid Polymer Electrolytes

使用固体聚合物电解质低温电催化氮氧化物还原

• 发表时间: 2007
• 作者: I.Ishibashi

Preparation of supported Pt-M catalysts (M = Mo and W) from anion-exchanged hydrotalcites and their catalytic activity for low temperature NO-H2-O2 reaction

阴离子交换水滑石负载型Pt-M催化剂（M=Mo和W）的制备及其对低温NO-H2-O2反应的催化活性

• DOI: 10.1016/j.apcatb.2007.02.012
• 发表时间: 2007-07-31
• 期刊: Applied Catalysis B-environmental
• 影响因子: 22.1
• 作者: Shinpei Hamada;S. Hibarino;K. Ikeue;M. Machida
• 通讯作者: M. Machida

Low-temperature Electrocatalytic NOx Reduction Using Solid Polymer Electrolytes

使用固体聚合物电解质低温电催化氮氧化物还原

• 发表时间: 2007
• 作者: I.Ishibashi; Y.Fujisaki; S.Hamada; K.Ikeue; S.Yamauchi; M.Kimura; M.Machida
• 通讯作者: M.Machida

Catalytic NO-H_2-O_2 Reaction over Pt/Mg-Al Oxides Prepared from PtCl_6-and Pt(NO_2)_4-Exchanged Hydrotalcites

PtCl_6-和Pt(NO_2)_4-交换水滑石制备Pt/Mg-Al氧化物催化NO-H_2-O_2反应

• 发表时间: 2006
• 作者: S.Hamada; K.Ikeue; M.Machida
• 通讯作者: M.Machida