Designed copper–amine complex as an efficient template for one-pot synthesis of Cu-SSZ-13 zeolite with excellent activity for selective catalytic reduction of NOx by NH3

Abstract

Low-cost copper-amine complex was rationally designed to be a novel template for one-pot synthesis of Cu-SSZ-13 zeolites. Proper confirmation and appropriate size make this complex fit well with CHA cages as an efficient template. The products exhibit superior catalytic performance on NH(3)-SCR reaction.

Environmentally-benign catalysts for the selective catalytic reduction of NOxfrom diesel engines: structure–activity relationship and reaction mechanism aspects

“…Therefore, it is highly imperative to improve the synthesis method to reduce the cost of Cu-SSZ-13 catalysts for the NH 3 -SCR process. Using the low-cost Cu-tetraethylenepentamine (Cu-TEPA) complex as a novel template, which is stable in a strong alkaline solution and matches the CHA cage structure very well, Ren et al 153,154 successfully designed a one-pot synthesis method for Cu-SSZ-13 catalysts, obtaining products with high Cu loading and high dispersion of Cu species simultaneously. Through adjusting the starting compositions in the precursor gels, Cu-SSZ-13 zeolites with different Si/Al ratios could be synthesized.…”

Understanding the structure directing action of copper–polyamine complexes in the direct synthesis of Cu-SAPO-34 and Cu-SAPO-18 catalysts for the selective catalytic reduction of NO with NH3

“…In previous papers reporting the direct synthesis of Cu-SSZ-13, [7] Cu-SAPO-34 [9][10][11] and Cu-SAPO-18 [12] using Cu The main difference between the method of synthesis in this work from that of Corma and co-workers, [12] is that whereas a template, N,N-dimethyl-3,5-dimethylpiperidinium, is used in that work to direct the synthesis of the SAPO-18, entraining Cu 2+ and/or Cu 2+ complex at the same time, in our synthesis it is the Cu-232…”

“…[6][7][8][9][10][11][12] Calcination then releases the Cu 2+ cations to extra-framework sites distributed throughout the crystals and removes the need for a cation-exchange step. This process was first demonstrated for SAPO STA-7, [6] and subsequently for SSZ-13, [7] SAPO-34, [9][10][11] and very recently for SAPO-18 [12] giving active, selective and hydrothermally stable catalysts. The details of the mechanism by which the calcination of the complex-bearing precursor to SAPO STA-7 gives a porous, acidic framework with dispersed copper cations has been followed by ex situ UV-visible spectroscopy and by in situ microcrystal IR spectroscopy.…”

A novel one-pot synthesized CuCe-SAPO-34 catalyst with high NH3-SCR activity and H2O resistance

“…Hence, Ce is a promising candidate for improving the NH 3 -SCR performance of catalysts, especially under severe conditions. Lately, copper-tetraethylenepentamine (Cu-TEPA) has been designed to fit the CHA structure [4], and used in the one-pot hydrothermal synthesis method to prepare Cu-SAPO-34 directly [5] which showed high SCR activity and hydrothermal stability [17]. The method is easy to perform, with facile control of Cu loading, and might be applicable at industrial scale.…”

“…Copper-containing small-pore zeolites such as Cu-SAPO-34 and Cu-SSZ-13 have been attracting increasing attention as superior NH 3 -SCR catalysts [1][2][3][4][5][6]. The Cu-SAPO-34 catalyst showed excellent SCR activity over a wide range of temperature and quite outstanding hydrothermal stability at high temperatures [7][8][9].…”