Hydrazine vapor modified waste molecular sieves to reconstitute 13X zeolites for efficient wide scale domain CO2 capture

The capture of CO 2 from ambient air (400 ppm) has become a critical issue in combating climate change. In this study, a novel recombinant 13X zeolite (RS13X) with an Faujasite (FAU) structure was synthesized by transforming discarded Linde type A (LTA)-structured 4 A molecular sieves through alkali fusion. This material was subsequently modified with hydrazine (HZ) vapor to produce HZ-RS13X, which significantly enhances the pore structure of RS13X, leading to excellent CO 2 adsorption performance across a range of concentrations. Specifically, HZ-RS13X demonstrates excellent adsorption capacities of 2.16 mmol/g at 400 ppm, 6.14 mmol/g at 10,000 ppm, and 7.89 mmol/g at 100,000 ppm, highlighting its efficacy for industrial CO 2 emissions. Additionally, HZ-RS13X excels in the selective separation of CO 2 from CH 4 and N 2 , exhibiting high ideal adsorbed solution theory (IAST) selectivity values of 335 for a CO 2 /N 2 mixture (10/80) and 260 for a CO 2 /CH 4 mixture (50/50). Characterization results, along with grand canonical Monte Carlo (GCMC) simulations, reveal that HZ vapor modification enhances CO 2 adsorption modes of RS13X beyond those achieved through conventional carbamate generation methods. HZ-RS13X offers substantial CO 2 capture potential across a wide range of concentrations, from atmospheric levels to industrial emissions, presenting a promising strategy for solid-state CO 2 capture.