One-pot synthesis of Cu-SAPO-34 catalyst using waste mother liquid and its application in the selective catalytic reduction of NO with NH3

One‐pot facile synthesis of Cu‐SAPO‐34 via addition of tetraethylenepentamine and its enhanced catalytic activity in selective catalytic reduction of NOx with NH3

“…Additionally, repeated ion‐exchange processes significantly increases the complexity of the synthesis process 10 . Fortunately, it is found that one‐step methods can successfully overcome this difficulty 9,11,12 . Recently, Xiao and co‐workers used a specified low‐cost copper complex with tetraethylenepentamine (TEPA) as a unique template, achieving a rational one‐pot synthesis of Cu‐SSZ‐13 zeolites with a SiO 2 /Al 2 O 3 molar ratio of 8–15, which was designated as Cu‐ZJM‐1.…”

“…10 Fortunately, it is found that one-step methods can successfully overcome this difficulty. 9,11,12 Recently, Xiao and co-workers used a specified low-cost copper complex with tetraethylenepentamine (TEPA) as a unique template, achieving a rational one-pot synthesis of Cu-SSZ-13 zeolites with a SiO 2 /Al 2 O 3 molar ratio of 8-15, which was designated as Cu-ZJM-1. Cu-ZJM-1 has a substantially greater copper content (>9.5%) than that afforded using the typical Cu 2+ ion-exchange technique, and better dispersion of copper cations.…”

One-Pot Synthesis of the Cu-SAPO-18 Catalyst Using Waste Mother Liquid and its Application in the SCR of NOx with NH3

“…So, amounts of surplus mother liquid must be separated and discarded as liquid waste at the end of the synthesis. Meanwhile, this synthetic method needs an excess of reagents and reactants to afford a high zeolite yield . As a result, the generated liquid waste contains abundant organic species such as organic amine templates which are usually expensive and hazardous and require thermal processing to eliminate it after hydrothermal synthesis and inorganic species such as silicon oxide, alumina, phosphate, copper ion, sulfate, and other reactants, which are not involved in crystallization.…”

“…Pengthamkeerati et al demonstrated that mother liquid can promote synthetic yield of nanosilicalite-1. Bing et al used waste mother liquid to synthesize Cu-SAPO-34 and proved that the resulting catalysts showed a similar crystallographic structure and morphology to those of the initial Cu-SAPO-34 catalyst. Xi et al .…”

“…Pengthamkeerati et al 23 demonstrated that mother liquid can promote synthetic yield of nanosilicalite-1. Bing et al 14 used waste mother liquid to synthesize Cu-SAPO-34 and proved that the resulting catalysts showed a similar crystallographic structure and morphology to those of the initial Cu-SAPO-34 catalyst. Xi et al 24 succeeded in synthesizing the hierarchical SAPO-34 catalysts using mother liquid, and zeolite can maintain high SCR activity and structural characteristics even after three cycles of mother liquid.…”