Objective The aim is to investigate the changes in carrier structure and framework during solid ion exchange process. Additionally, the CO adsorption capacity of the adsorbent under various temperature treatments was investigated.

Methods Firstly, NaY was prepared by hydrothermal synthesis method, followed by obtaining NH₄Y through ammonia ion exchange method, HY carrier was obtained after calcining, CuCl and HY were mechanically mixed in specific proportions, and calcined at 250 ℃, 350 ℃, 450 ℃, 550 ℃, 650 ℃, and 750 ℃ in a nitrogen atmosphere, a series of samples were finally obtained and characterized by X-ray diffraction (XRD), Ar adsorption/desorption, scanning electron microscopy (SEM), and other characterization methods.

Results When the adsorbent was prepared by solid-state dispersion method, CuCl was mainly dispersed in single layer on HY carrier at low temperature range, and the isolated Cu⁺ was mainly formed by the ion exchange between CuCl and the hydroxyl group on the surface of the molecular sieve at high temperature range, and the molecular sieve structure would collapse with a further increase of temperature.

Conclusions The isolated Cu⁺ was more favorable to the adsorption of CO. The optimal calcination temperature for the mixed system of CuCl and HY was determined to be 650 ℃, and achieving not only a higher CO adsorption capacity but also improved CO/N₂ selectivity in the samples.