Center for Ordered Nanoporous Materials Synthesis, Division of Environmental Science and Engineering, POSTECH, Pohang, 37673, Korea.
Advanced Catalysts and Emission-Control Research Lab, Research & Development Division, Hyundai Motor Group, Hwaseong, Gyeonggi, 18280, Korea.
Angew Chem Int Ed Engl. 2017 Mar 13;56(12):3256-3260. doi: 10.1002/anie.201610547. Epub 2017 Jan 18.
Diesel engine technology is still the most effective solution to meet tighter CO regulations in the mobility and transport sector. In implementation of fuel-efficient diesel engines, the poor thermal durability of lean nitrogen oxides (NO ) aftertreatment systems remains as one major technical hurdle. Divalent copper ions when fully exchanged into high-silica LTA zeolites are demonstrated to exhibit excellent activity maintenance for NO reduction with NH under vehicle simulated conditions even after hydrothermal aging at 900 °C, a critical temperature that the current commercial Cu-SSZ-13 catalyst cannot overcome owing to thermal deactivation. Detailed structural characterizations confirm the presence of Cu ions only at the center of single 6-rings that act not only as a catalytically active center, but also as a dealumination suppressor. The overall results render the copper-exchanged LTA zeolite attractive as a viable substitute for Cu-SSZ-13.
柴油机技术仍然是满足移动和运输领域更严格的 CO 法规的最有效解决方案。在实施节能柴油机时，贫燃氮氧化物 (NO) 后处理系统的热耐久性差仍然是一个主要的技术障碍。二价铜离子完全交换到高硅 LTA 沸石中，即使在 900°C 的水热老化后，在车辆模拟条件下用 NH 进行 NO 还原时，仍表现出优异的活性保持能力，而当前的商业 Cu-SSZ-13 催化剂由于热失活而无法克服这一关键温度。详细的结构特征证实了 Cu 离子仅存在于单 6-环的中心，这些环不仅作为催化活性中心，而且作为脱铝抑制剂。总体结果表明，Cu 交换的 LTA 沸石作为 Cu-SSZ-13 的可行替代品具有吸引力。
