Study on the Simultaneous Catalytic Removal of Diesel Soot Particulates and Nitrogen Oxides

柴油机烟尘颗粒与氮氧化物同步催化脱除研究

• 批准号: 06559012
• 负责人: KAGAWA Shuichi
• 金额: $ 6.46万
• 依托单位: Nagasaki University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-06559012/
• 关键词: Diesel particulate; Nitrogen oxides; Simultaneous removal; Catalyst; Perovskite-type oxide; Spinel-type oxide; ディゼルパティキュレート

The present study has aimed to develop a new after-treatment catalytic system for diesel exhausts, socalled the simultaneous removal of NOx and diesel particulates (PM). The catalytic activity of perovskite-type (ABO_3), K_2NiF_4-type (A_2BO_4) and spinel-type (AB_2O_4) oxides for the simultaneous NOx-PM removal depended significantly on A- and B-site metal cations. Generally speaking, mixed metal oxides containing Co and Mn showed high activity but low selectivity to NOx reduction into N_2, while those containing Cu and Fe were excellent catalysts with moderate activity and high selectivity. The addition of alkali metal ions, especially K,was quite effective in promoting both the activity and selectivity. The mixed metal oxides were superior to transition metal simple oxides, their mechanical mixtures and supported Pt catalysts in the selectivity for NOx reduction.The mechanism of the simultaneous NOx-PM removal reaction was investigated by measuring the effect of gaseous composition … More of NOx and O_2. Nitrogen dioxide (NO_2) was effective for the ignition temperature of PM to decrease, and coexistence of O_2 with NOx was indispensable to enhance the NOx reduction into N_2. Based on the results, a possible reaction mechanism for the simultaneous NOx-PM removal was proposed which involves the oxidation of NO into NO_2 by O_2, the dissociative adsorption of NO_2 to give active oxygen species (O_<ad>), the formation of surface carbon species (intermediate) activated by O_<ad> and the attack of gaseous oxygen to intermediate.Honeycomb PM filter loaded with perovskite-type La_<0.9>K_<0.1>CoO_3 catalyst (catalytic filter) was prepared as a prototype of practical catalysts. After PM being trapped on the catalytic filter directly from the real diesel exhaust, the simultaneous NOx-PM removal reaction was performed in the flow of simulated diesel exhaust. The result strongly suggests the potentiality in the practical application of the present simultaneous NOx-PM removal process. Less

本研究旨在开发一种新的柴油尾气后处理催化系统，即同时去除NOx和柴油颗粒物（PM）。钙钛矿型（ABO_3）、k_2nif_4型（A_2BO_4）和尖晶石型（AB_2O_4）氧化物同时脱除NOx-PM的催化活性主要取决于A位和b位金属阳离子。总的来说，含Co和Mn的混合金属氧化物对NOx还原成N_2表现出高活性，但选择性较低，而含Cu和Fe的混合金属氧化物则表现出中等活性和高选择性的优异催化剂。碱金属离子特别是钾离子的加入对催化活性和选择性都有较好的促进作用。混合金属氧化物对NOx的选择性优于过渡金属简单氧化物、机械混合物和负载Pt催化剂。通过测定NOx和O_2的气相组成对NOx- pm同时脱除反应的影响，探讨了其机理。二氧化氮（NO_2）对降低PM的着火温度是有效的，而O_2与NOx的共存是促进NOx还原成N_2的必要条件。在此基础上，提出了同时脱除NOx-PM的可能反应机理：O_2将NO氧化为NO_2， NO_2解离吸附生成活性氧（O_<ad>）， O_<ad>活化生成表面碳（中间体），气态氧对中间体的攻击。制备了装载钙钛矿型La_<0.9>K_<0.1>CoO_3催化剂（催化过滤器）的蜂窝状PM过滤器，作为实用催化剂的原型。将真实柴油机尾气中的PM直接捕获在催化过滤器上后，在模拟柴油机尾气流中同时进行NOx-PM去除反应。结果表明，该工艺具有实际应用的潜力。少

项目成果

寺岡靖剛: "NOx-ディーゼルパティキュレート同時除去用La-K-Cu-V酸化物の活性相" 触媒. 37. 164-166 (1995)

Yasutaka Teraoka：“用于同时去除 NOx 和柴油颗粒的 La-K-Cu-V 氧化物的活性相”催化剂 37. 164-166 (1995)

Y.Teraoka: "Simultaneous Catalytic Removal of Nitrogen Oxides and Diesel Soot Paticulate over Perovskite-type Oxides" Catalysis Today. 27. 107-113 (1996)

Y.Teraoka：“钙钛矿型氧化物上氮氧化物和柴油机烟灰颗粒的同时催化去除”今日催化。

Y.Teraoka: "Simultaneous Catalytic Removal of Nitrogen Oxides and Diesel Soot Particulate over Perovskite-type Oxides" Catalysis Today. (in press).

Y.Teraoka：“通过钙钛矿型氧化物同时催化去除氮氧化物和柴油机烟灰颗粒”今天的催化。

Y.Teraoka: "Simultaneous Catalytic Removal of Nitrogen Oxides and Diesel Soot Particulate over Perovskite-type Oxides" Environmental Catalysis-for a better World and Life-(Eds.G.Centi et al.). 77-79 (1995)

Y.Teraoka：“通过钙钛矿型氧化物同时催化去除氮氧化物和柴油机烟灰颗粒”环境催化——为了更美好的世界和生活——（Eds.G.Centi 等人）。

W.F.Shangguan: "Kinetics of Soot-O_2,Soot-NO and Soot-O_2-NO Reactions over Spinel-type CuFe_2O_4 Catalyst" Applied Catalysis,B;Environmental. (in press).

W.F.Shangguan：“尖晶石型CuFe_2O_4催化剂上Soot-O_2、Soot-NO和Soot-O_2-NO反应的动力学”，应用催化，B；环境。