OSDA-free and steam-assisted synthesis of PHI type zeolite showing a unique CO2 adsorption behaviour

A green synthesis of PHI zeolite was achieved by OSDA-free steam-assisted interzeolite conversion from FAU. K + -, Rb + -, and Cs + -PHI zeolites exhibit sigmoid CO 2 adsorption isotherms in which the sharp increase shifts depending on the cation radius.