One promising approach to addressing global warming involves capturing storing and reusing greenhouse gas emissions. Following separation, usually via adsorption, potential CO2 emissions capture rates can reach up to 90%. Hence, It is crucial to enhance efficiency and reduce costs associated with CO2 capture and utilization processes. This study explores the synthesis of geopolymer/zeolite composites based on phosphate amine tailings for CO2 capture applications. These materials offer benign environmental advantages and demonstrate reversible adsorption and desorption of carbon dioxide. The research compares the adsorption capacities of the synthesized materials with the geopolymer and the commercial Zeolite 13X, assessing their performance for the CO2, H2, and CO adsorption at various temperatures (30, 50, and 100°C). Furthermore, the samples underwent thorough characterization by XRF, XRD, FTIR, SEM, EDS, XPS, NMR, micro-CT, density, BET surface area, and porosity. The high surface area and low porosity of the materials influence directly in the adsorption capacity, which increases with the addition of more zeolite on the composite. The incorporation of 30% (w/w) of zeolite to the composite yielded notable adsorption capacities at 30 ºC and 1 bar (~ 2.6 mmol·g− 1).