Methods for producing hierarchical mesoporous beta zeolite

A method for increasing a molar ratio of silicon to aluminum in a hierarchical mesoporous beta zeolite, the method comprising:

• contacting a beta zeolite having a hierarchical mesoporous structure with an ammonium nitrate solution comprising a molarity from 0.1 M to 1.0 M at a temperature from 25° C. to 100° C. for a time of greater than or equal to 1 hour to produce an intermediate hierarchical mesoporous beta zeolite having (a) a molar ratio of silicon to aluminum of less than 12.5, (b) a total pore volume of greater than or equal to 0.3 cm3/g, and (c) an average mesopore size of greater than 8 nm, wherein contacting causes ion exchange of sodium ions with ammonium ions in the hierarchical mesoporous beta zeolite;
• calcining the intermediate hierarchical mesoporous beta zeolite at a temperature of greater than or equal to 500° C. for a time of greater than or equal to 1 hour;
• and
• treating the intermediate hierarchical mesoporous beta zeolite with an acidic solution having a molarity from 0.1 M to 1.0 M at a temperature from 25° C. to 100° C. for a time of greater than or equal to 1 hour to produce the hierarchical mesoporous beta zeolite having (e) a molar ratio of silicon to aluminum of greater than 12.5, (f) a total pore volume of greater than or equal to the total pore volume of the intermediate hierarchical mesoporous beta zeolite, and (g) an average mesopore size of greater than or equal to the average mesopore size of the intermediate hierarchical mesoporous beta zeolite.