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70℃下，用电化学方法成功地实现了过量O_2存在下NO_x的还原。H+导电的固体聚合物电解质（SPE）在Pt阴极上催化NO-H_2反应生成Ca+ C476。结果表明，Pt阴极上的电化学析氢比原料气中的H_2分子对NO的反应活性更高。由于Pt表面被稳定的硝酸根（NO_3）覆盖，阻碍了氧在Pt表面的吸附，从而抑制了H_2-O_2的竞争反应。SPE电池与负载型Pt催化剂的结合可广泛应用于新型低温脱硝工艺。在Nafion-117 H^+导电聚合物膜上制备的Cu-Pd和Cu-Pt双金属阴极上，也进行了硝酸根离子（NO_3）的电催化还原。通过对膜电极组件（MEA）施加直流电，H_2在阴极上析出，导致NO_3^-在阴极室中单调降解。的. NO_3^-还原反应是连续进行的，Cu显著提高了NO_3^-还原为NO_2^-的第一步催化活性。分别具有38和20原子% Cu的Cu-Pd和Cu-Pt阴极表现出最高的还原速率。产物的选择性也取决于Cu的含量。Cu-Pd阴极对NO_2的还原活性高，对NO_2^-的选择性低，对NH_4^+的选择性高。CO_2的加入使硝酸盐还原反应的pH值降低到7以下，并使反应平衡2NO_3 + 5H_2 + N_2 + 2 OH ^- + 4H_2O发生移动，从而加快了硝酸盐还原反应的速率。

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: 奥野真史;李家賢一;砂田保人;安居院 綾子;M.A.Hasnat
• 通讯作者: M.A.Hasnat

第5版 実験化学講座25巻(執筆分担-1.3.2酸化物触媒)

第五版实验化学课程第25卷（写作分享-1.3.2氧化物催化剂）

• 发表时间: 2006
• 作者: 奥野 真史;李家 賢一;砂田 保人;安居院 綾子;町田正人
• 通讯作者: 町田正人

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

• 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: Hamada, S.;Hibarino, S.;Machida, M.
• 通讯作者: Machida, M.

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
• 期刊: Applied Catalysis B : Environmental Vol.71,No.1-2
• 作者: S.Hamada;K.Ikeue;M.Machida
• 通讯作者: M.Machida

金属電極-イオン伝導性高分子固体電解質膜アセンブリによる硝酸イオン除去

金属电极-离子导电聚合物固体电解质膜组件去除硝酸离子

• 发表时间: 2007
• 作者: 奥野真史;李家賢一;砂田保人;安居院 綾子
• 通讯作者: 安居院 綾子