Method for the preparation of a molecular sieve of the CHA-type

A method for the preparation of a molecular sieve of the CHA-type having an amount of stacking disorder of up to 4%, wherein the method comprises the steps of:

• (i) preparing a synthesis mixture comprising
• (a) a non-molecular sieve source of both silicon and aluminum selected from the group consisting of precipitated silica-alumina, amorphous silica-alumina, kaolin, and mixtures thereof;
• (b) an organic structure directing agent (OSDA) which is a tetraethylammonium cation, a methyltriethylammonium cation, or a mixture thereof;
• (c) water;
• (d) a crystalline molecular sieve containing six-ring structural features is selected from FAU;
• and
• (e) an alkali hydroxide (A) which is sodium hydroxide;
• in molar ratios of
• SiO2/Al2O3 8 to 60
• OSDA/SiO2 0.01 to 1.0
• water/SiO2 2 to 200
• A/SiO2 more than 0 and up to 0.25;
• wherein the molar ratio of (the total amount of non-molecular sieve source of silicon and non-molecular sieve source of aluminum) to (crystalline molecular sieve containing six-ring structural features) is in the range of 99/1 to 5/95, and wherein the ratio of total hydroxide to silica is below or equal to 0.6;
• (ii) subjecting the mixture to conditions capable of crystallizing the molecular sieve of the CHA-type;
• and
• (iii) separating the molecular sieve of the CHA-type.