| 浸渍/共沉淀法对BaO改性单Pd催化剂净化甲醇汽油车尾气性能的影响 |
| BaO Modified Pd-Based Catalysts: Synthesis by Impregnation/Co-Precipitation and Application in Gasoline-Methanol Exhaust Purification |
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| 摘要: 采用浸渍和共沉淀两种方法分别制备了BaO改性的Pd/CeO2-ZrO2-La2O3-Al2O3催化剂.运用N2吸附-脱附,X射线衍射(XRD),H2程序升温还原(H2-TPR),NH3程序升温脱附(NH3-TPD),透射电子显微镜(TEM)和X射线光电子能谱(XPS)对催化剂进行表征,并考察其对甲醇,CO,C3H8和NO的催化性能.活性测试结果表明,BaO的引入可明显改善Pd催化剂对甲醇,CO,C3H8和NO的催化活性,且浸渍法最佳,起燃温度(T50)分别降低了43,31,45和35℃.XRD,H2-TPR及XPS结果表明,浸渍法引入BaO主要通过表面改性方式,强化Pd-Ce界面间的相互作用,改善催化剂的还原性能,进而提高催化剂的低温活性;而共沉淀法则是通过结构改性方式增加CeO2晶格缺陷,加速活性氧物种的流动,Ce3+浓度的增加是促使CO氧化活性显著提高的主要原因. |
| 关键词: 氧化钡 钯 铈 甲醇 催化转化 |
| 基金项目: 国家自然科学基金(No.51408076,11405113),四川省教育厅重点科研基金(No.14ZA0163),成都信息工程学院科研人才基金(No.J201416)资助项目. |
| Abstract: Barium oxide was developed to modify palladium catalysts supported on CeO2-ZrO2-La2O3-Al2O3 (CZLA) compound oxides by impregnation/co-precipitation methods. Low temperature N2 adsorption-desorption, X-ray diffraction (XRD), H2-temperature-programmed reduction (H2-TPR), NH3-temperature programmed desorption (NH3-TPD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) were employed to characterize the influence of the preparation method on physicochemical properties of the catalyst. Catalytic activity performance for methanol, CO, C3H8 and NO conversion was evaluated. Catalytic activity results show that the addition of BaO has a positive effect on the conversion of all pollutants, and the best results are achieved by the impregnation method. The light-off temperature decreases by 43, 31, 45 and 35 ℃, respectively. The XRD, H2-TPR and XPS results confirm that the impregnation method is mainly based on the surface modification. The enrichment of Ba2+ strengthens the Pd-Ce interaction in Pd-Ce interface, promoting the reductive ability, thus increasing the catalytic activity at low temperature. The co-precipitation method results in structure disorder and additional anion vacancies accompanied by the formation of more Ce3+, which may be beneficial to the conversion of CO. |
| Keywords: barium oxide palladium ceria methanol catalytic activity removal |
| 投稿时间：2014-04-24 修订日期：2014-09-08 |
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| 张雪乔,田浩杞,叶芝祥,陈耀强.浸渍/共沉淀法对BaO改性单Pd催化剂净化甲醇汽油车尾气性能的影响[J].无机化学学报,2015,31(1):166-176. |
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