| 一步水热合成Cu-SSZ-13分子筛选择性催化C3H6还原NO | |
| Selective Catalytic Reduction of NO with C3H6 over One-Step Hydrothermal Synthesized Cu-SSZ-13 Catalysts | |
| 摘要: 采用铜胺配合物（Cu2+-四乙烯五胺，Cu-TEPA）作为结构导向剂，通过一步水热法合成不同铜铝比（nCu/nAl）和硅铝比（nSi/nAl）的Cu-SSZ-13分子筛催化剂，研究其在贫燃条件下丙烯选择性催化还原NO（C3H6-SCR）的性能。当nCu/nAl=2、nSi/nAl=6时2.0Cu-SSZ-13（6）催化剂具有最好的低温脱硝活性，200℃时NO转化率超过80%，在250~300℃可实现100%脱硝效率和~100% N2选择性，同时具有较强的抗水、抗硫性能。为研究不同nCu/nAl和nSi/nAl对催化剂物理化学特性的影响，通过X射线衍射（XRD）、扫描电子显微镜（SEM）、N2吸附-脱附测试、H2程序升温还原（H2-TPR）、氨气程序升温脱附（NH3-TPD）、紫外可见光谱（UV-Vis）等手段对样品进行表征。结果表明，2.0Cu-SSZ-13（6）具有最佳的脱硝性能，这是因为其具有最大的比表面积、最强的表面酸性和分布最多的孤立态Cu2+离子。Cu-SSZ-13上丰富的酸性位可以有效促进C3H6和NO的吸附和活化，SSZ-13分子筛八元环中孤立的Cu2+离子具有良好的氧化还原性能，是C3H6-SCR反应的主要活性位。随着nCu/nAl的增加，孤立的Cu2+离子会在分子筛表面迁移、集聚形成CuO物种，从而导致C3H6-SCR活性下降。 | |
| 关键词: Cu-SSZ-13 选择性催化还原 丙烯 NO Cu2+ 硅铝比 | |
| 基金项目: 江苏省自然科学基金（No.BK20181161）、国家自然科学基金（No.51278095）、江苏省高校“青蓝工程”项目（2017）和江苏省“333工程”科研项目（2018）资助。 | |
| Abstract: To investigate the performance of Cu-SSZ-13 for selective catalytic reduction of NO with C3H6 under lean-burn conditions, Cu-SSZ-13 with different nCu/nAl and nSi/nAl were prepared by one-step hydrothermal synthesis method using Cu2+-tetraethylenepentamine (Cu-TEPA) as a structure directing agent. The Cu-SSZ-13 catalyst with nCu/nAl=2 and n Si/nAl=6 had the best low-temperature activity, which could reach over 80% NO conversion at 200℃, and 100% NO conversion and ~100% N2 selectivity at 250~300℃. In addition, it also exhibited moderate resistance to SO2 and H2O. The influence of different nCu/nAl and nSi/nAl on the physicochemical properties of the catalysts were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), N2 adsorption-desorption test, temperature programmed reduction of H2 (H2-TPR), temperature programmed desorption of ammonia (NH3-TPD), ultraviolet -visible spectroscopy (UV-Vis) and other characterization methods. According to the results of characterizations, the excellent catalytic activity of 2.0Cu-SSZ-13(6) obtained with nCu/nAl=2 and nSi/nAl=6 may relate to the largest specific surface area, the strongest surface acidity and the highest distribution of isolated Cu2+ ions. Abundant acid sites on Cu-SSZ-13 can effectively promote the adsorption and activation of C3H6 and NO. The isolated Cu2+ ions in the 8membered rings of SSZ-13 had great redox performance, which were the main active sites for the C3H6-SCR reaction. As the nCu/nAl increased, the isolated Cu2+ ions would migrate and accumulate on the surface of the zeolite catalysts to form CuO species, resulting in the decrease in the activity of C3H6-SCR reaction. | |
| Keywords: Cu-SSZ-13 selective catalytic reduction C3H6 NO Cu2+ nSi/nAl | |
| 投稿时间：2020-12-07 修订日期：2021-03-26 | |
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| 王聪颖,周皞,杨迪,张恒,赵辉爽,叶必朝,苏亚欣.一步水热合成Cu-SSZ-13分子筛选择性催化C3H6还原NO[J].无机化学学报,2021,37(5):853-866. | |
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