Methods for synthesizing a mesoporous nano-sized zeolite beta are described. The method may include mixing an aqueous base solution with hexadecyltrimethylammonium bromide (CTAB) to form a first solution; adding nano-sized zeolite particles having a particle size of less than or equal to 100 nm to the first solution to form a second solution. The nano-sized zeolite particles include a microporous framework with a plurality of micropores having diameters of less than or equal to 2 nm and a BEA framework type. The method may further include transferring the second solution to an autoclave operated at 25° C. to 200° C. for 3 to 24 hours to form a colloid; drying the colloid at 100° C. to 200° C. for 8 to 36 hours without washing the colloid to form a zeolite precursor; and calcining the zeolite precursor at 250° C. to 600° C. for 1 to 8 hours to form the mesoporous nano-sized zeolite beta.