Investigation of Suitable Templates for One-Pot-Synthesized Cu-SAPO-34 in NO<sub><i>x</i></sub> Abatement from Diesel Vehicle Exhaust
Jinpeng Du, Xiaoyan Shi, Yulong Shan, Wenshuo Zhang, Yunbo Yu, Wenpo Shan, Hong He
Abstract
The control of NOx emission from diesel vehicles is of great importance to the environment, and Cu-SAPO-34 is considered to be an effective catalyst for the abatement of NOx from diesel vehicles. Along with catalytic activity, hydrothermal stability is a key property for NOx abatement catalysts. The attack of Cu species and framework atoms by H2O may result in activity loss under both low/high temperature humid conditions, which are inevitable in practical application. Therefore, apart from good catalytic activity, hydrothermal stability under both low/high temperatures for Cu-SAPO-34 is also critical for NOx control in diesel vehicles. Three Cu-SAPO-34 samples were prepared by a one-pot hydrothermal method using propylamine, triethylamine, and morpholine, with Cu-TEPA (tetraethylenepentamine) as the cotemplate. The NH3-SCR activity and the effects of hydrothermal aging at 70 and 800 °C on these Cu-SAPO-34 samples were investigated. The type of cotemplate can affect the Si and Cu species in one-pot-synthesized Cu-SAPO-34 catalysts, so that the catalytic activity as well as the low/high temperature hydrothermal stability is affected by the choice of template. Generally speaking, Cu-SAPO-34 prepared using PA as cotemplate showed superior catalytic activity and hydrothermal stability under low/high temperatures compared with the other two catalysts, which makes PA a more suitable template for one-pot-synthesized Cu-SAPO-34 for use in NOx abatement from diesel vehicle exhaust.