由新型铜胺络合物模板剂设计合成活性优异的Cu-SSZ-13分子筛

摘要

The modern synthesis of zeolites typically uses organic structure-directing agents. Therefore, the developing of new templates is part of zeolite research. The design and synthesis of Cu-SSZ-13 using a novel template of a low-cost copper amine complex (Cu2+ coordinated with tetraethylenepentamine) were reported, where the copper amine complex is both a template for synthesizing the SSZ-13 structure and a source of copper species in the zeolite. The calculated size of the complex (0.728 nm × 0.922 nm) matches well with the CHA cages (0.73 nm x 1.2 nm), which are the building units of the SSZ-13 zeolite. Various techniques were used to investigate the chemical and physical properties of the synthesized zeolite. The results showed that the sample has the SSZ-13 zeolite structure, high crystallinity, adjustable Si/Al ratios, and controllable copper loading. Catalytic tests using the selective catalytic reduction of Noχ with NH3 showed that the Cu-SSZ-13 was a superior catalyst, and it can be important for the abatement of environmentally harmful Noχ.%以低廉的铜胺络合物为新型模板剂,成功地合成了含铜的SSZ-13沸石分子筛(Cu-ZJM-1).在合成过程中,铜胺络合物既是模板分子,又是催化活性组分铜物种的直接来源.理论计算表明,该模板分子的构型与尺寸恰好与构成SSZ-13分子筛结构的CHA笼相匹配,因而可以成功地导向该沸石分子筛结构.采用X射线衍射、扫描电镜、氮气吸附、红外、紫外-可见吸收光谱、差热-热重分析、氨气程序升温脱附及氢气程序升温还原等手段对样品的性质及模板分子的状态进行了系统表征.结果表明,所制Cu-ZJM-1样品为结晶度很高的SSZ-13沸石结构,硅铝比和铜负载量可调且铜处于高分散状态,在NH3选择催化还原氮氧化物反应中表现出优异的催化性能.