Organosilane-assistant synthesis of hierarchical SAPO-34 aggregates with superior MTO performance

Morphology control of SAPO-34 and its catalytic performance for methanol to olefin reaction

“…A large number of literature reports have also proved that these optimizations have greatly promoted the improvement of SAPO-34 catalytic performance in the MTO reaction and its application effect in industrial development. 15–18 Yu's group synthesized nanosized hierarchical SAPO-34 catalysts by the seed-assisted method. 19 Compared to the conventional micron-sized SAPO-34 zeolites, the nanosized hierarchical SAPO-34 zeolites showed superior performance in the MTO reaction with 4-fold prolonged catalytic lifetime and remarkably improved selectivity of ethylene and propylene reaching up to 85.0%.…”

Study of the Catalytic Oxidation Mechanism and Apparent Kinetics of NO Oxidized by H2O2 with Fe/β, Fe/SSZ-13, and Fe/ZSM-5

“…According to the above characterization of Fe/zeolite catalysts, the mechanism of catalytic oxidation can be summarized as follows: H 2 O 2 (1.78 eV) itself as an effective oxidant can oxidize NO, as shown in eqs and ; it is known that H 2 O 2 can produce • OH with high oxidation ability (2.80 eV) under the action of Fe/zeolite catalysts, and a series of reactions – occur; ,− excess H 2 O 2 will generate HO 2 • radicals, which have less oxidizing ability (1.65 eV) than • OH, and will produce some side reactions –, ,, so it is consistent with the conclusion that excess H 2 O 2 will lead to NO removal decreases; since a small amount of O 2 will be generated during the reaction, O 2 (capture intermediate) can produce • O by consuming • OH, and NO can be oxidized to NO 2 by eqs and . Although • O (2.05 eV) has less oxidizing ability than • OH, the amount of O 2 produced in the reaction is so small that the effect is negligible; finally, the efficient removal of NO is also related to the content of Brønsted acid sites.…”

Improvement of adsorption and catalytic properties of zeolites by precisely controlling their particle morphology

“…44 Similarly, hierarchical porous ZSM-5 obtained by treating with NaOH and TPAOH solution was used to upgrade bio-oil and yielded 45.2 mg of aromatics per gram of bio-oil. 43 In the last decade, various zeolite nanocrystallite aggregates with large numbers of intercrystallite gaps or pores have been synthesized by altering the synthesis gel composition [46][47][48] or adding surfactants, e.g. cetyltrimethylammonium bromide (CTAB), 49 polydiallydimethylammonium chloride (PDADMAC), 50,51 and amino acid.…”