LOW-TEMPERATURE SYNTHESIS OF HIGH-PURITY AFX ZEOLITE

    公开(公告)号:US20220332595A1

    公开(公告)日:2022-10-20

    申请号:US17764224

    申请日:2020-09-18

    IPC分类号: C01B39/48

    摘要: The invention relates to a process for synthesizing a high-purity AFX zeolite, comprising at least the following steps:
    i) mixing, in an aqueous medium, of at least one source of silicon (Si) in SiO2 oxide form, at least one source of aluminum (Al) in Al2O3 oxide form, a nitrogenous organic compound of 1,6-bis(methylpiperidinium)hexane dihydroxide type, and at least one source of at least one alkali metal chosen from lithium, potassium or sodium, and the mixture of at least two of these metals, until a homogeneous precursor gel is obtained; ii) hydrothermal treatment of said precursor gel obtained at the end of step i) at a temperature of between 75° C. and 95° C., limits included, for a period of between 40 and 100 hours, limits included, to obtain a solid AFX-structure crystalline phase, termed “AFX zeolite”. The invention also relates to the high-purity AFX zeolite obtained.

    LOW-TEMPERATURE SYNTHESIS OF CATALYST BASED ON ZEOLITE AFX AND APPLICATION THEREOF IN NH3-SCR

    公开(公告)号:US20220339612A1

    公开(公告)日:2022-10-27

    申请号:US17764264

    申请日:2020-09-18

    摘要: The invention relates to a process for preparing a catalyst based on an AFX zeolite exchanged with at least one transition metal, comprising at least the following steps:
    i) mixing, in an aqueous medium, of at least one source of silicon (Si) in SiO2 oxide form, at least one source of aluminum (Al) in Al2O3 oxide form, 1,6-bis(methylpiperidinium)hexane dihydroxide, and at least one source of at least one alkali metal, until a homogeneous precursor gel is obtained; ii) hydrothermal treatment at a temperature between 75° C. and 95° C., limits included; iii) at least one ion exchange with a solution comprising at least one species capable of releasing a transition metal, iv) heat treatment by drying followed by at least one calcination under a stream of air at a temperature between 400 and 700° C. The invention also relates to the catalyst obtained and to the use thereof for the selective reduction of NOx.