High yield synthesis of high-silica chabazite by combining the role of zeolite precursors and tetraethylammonium: SCR of NOx

Abstract

The synthesis of chabazite with high solid yields is achieved by the rational combination of directing effects of a source of Si and Al coming from USY zeolites and the inexpensive tetraethylammonium.

Fe‐Containing Zeolites for NH3‐SCR of NOx: Effect of Structure, Synthesis Procedure, and Chemical Composition on Catalytic Performance and Stability

“…Thus, a decrease in the manufacturing costs by finding a less expensive OSDA is a matter of interest for industrial applications of CHA‐related catalysts . In this sense, we recently described the synthesis of high‐silica CHA material by using the less expensive and more environmentally friendly tetraethylammonium (TEA, see Figure B) cation as OSDA by following a simple zeolite‐to‐zeolite transformation with a high‐silica USY zeolite as the initial silicon and aluminium source …”

Conversion of Y into SSZ-13 zeolites and ethylene-to-propylene reactions over the obtained SSZ-13 zeolites

“…SSZ-13 zeolites have been synthesized via various methods, including direct synthesis (from precursors of silica and alumina) and conversion of zeolite Y. For the synthesis of SSZ-13s, various templates, such as N,N,Ntrimethyl-1-adamantanamine iodide (TMAda-I) [5,7], TMAda-OH [8][9][10][11][12], choline chloride [13,14], copper-tetraethylenepentamine (Cu-TEPA) [15][16][17], tetraethylammonium hydroxide (TEA-OH) [18], benzyltrimethylammonium hydroxide [19], and N,N,Ndimethylethylcyclohexylammonium bromide [20] have been used despite several reports of its template-free [21][22][23][24] synthesis.…”

Recent Progress in Atomic-Level Understanding of Cu/SSZ-13 Selective Catalytic Reduction Catalysts

“…This explains why hydrothermal aging effects have been so extensively studied [39][40][41][52][53][54]. Prior studies have suggested that Cu/SSZ-13 durability enhancement can be achieved in a number of ways: (1) composition optimization, that is, choosing optimized Si/Al and Cu/Al ratios [31]; (2) zeolite particle size optimization [55]; (3) new synthesis methods development [30,[56][57][58][59]; and (4) introduction of stability enhancement additives. Among these, some appear not to be as useful as others.…”

“…From our own experience, too large of a particle size can even be detrimental due to poor heat dissipation during structure directing agent (SDA) combustion that induces rather serious thermal degradation of the SSZ-13 substrate. Also, new Cu/SSZ-13 synthesis methods, including one-pot ones, do not necessarily lead to catalysts with better stability than catalysts prepared with more traditional solution ion-exchange methods [30,[56][57][58][59].…”