Method of making SSZ-13 zeolites with high acidity and low silica to alumina ratio (SAR)

A method of forming a catalyst for use in low temperature NOx conversion, wherein the method comprises the steps of:

• forming an SSZ-13 zeolite containing one or more metal cations as part of the SSZ-13 zeolite according to a method comprising the steps of:
• a) providing a source of silica;
• b) providing a source of alumina;
• c) providing a structure directional agent (SDA);
• wherein the amount of the structure directing agent (SDA) and the silica (SiO2) source provided is defined by a SDA:SiO2 molar ratio that ranges from 0.03 to 0.05;
• d) providing a source of metal cations;
• e) mixing the source of silica and alumina with the SDA and the source of metal cations in water to form a gel composition;
• f) heating the gel composition to a crystallization temperature that is in the range of about 140° C. to about 180° C.;
• g) maintaining the gel composition at the crystallization temperature for a time period that ranges from 9 hours to 24 hours;
• h) allowing the gel to crystallize and precipitate;
• the gel composition forming a crystalline precipitate of the SSZ-13 zeolite and a mother liquid;
• and
• i) separating the crystalline precipitate from the mother liquid;
• wherein the formed SSZ-13 zeolite has a silica to alumina (SiO2:Al2O3) molar ratio (SAR) that is less than 16:1;
• a morphology that includes one or more of cubic, spheroidal, or rhombic particles;
• and a crystal size that is in the range of about 0.1 micrometer (μm) to 10 μm;
• providing a source of at least one transition metal;
• and
• subjecting the SSZ-13 zeolite and the source of the transition metal to an ion exchange, impregnation, or isomorphous substitution process;
• wherein the at least one transition metal is substituted for the metal cations in the SSZ-13 zeolite, thereby forming the catalyst;
• wherein the amount of the transition metal (TM) and aluminum present in the catalyst is further defined by a TM:Al molar ratio in the range of 0.5 to 1.0.