Study on Zinc-Modified Adsorbent for Adsorption of Trace CO₂ in Electronic Special Gas BF₃

Usually, the ion implantation gases used in semiconductor production are required to be extremely high in purity. Due to the presence of trace CO₂ in electronic special gas BF₃, the quality of the material is significantly affected, which makes it crucial to impose control on CO₂ content. Unlike a series of blank adsorbents reported in other studies, the zinc-loaded adsorbents prepared in this study are intended for the adsorption of CO₂ from CO₂/BF₃. Firstly, the materials were characterized by XRD, BET, SEM-EDS and TG-DSC analysis, etc., and the breakthrough curves of the adsorbents as obtained under different preparation conditions were investigated at 20 °C and 200 kPa. The results show that the adsorption performance reached the optimal level when the activation temperature was 450 °C and a 13X molecular sieve was impregnated by 0.15 mol/L Zn(NO₃)₂. Moreover, compared with the Zn-13X, the breakthrough time was reduced to 69% and 44% in two adsorption cycles, respectively. Finally, FTIR was used to reveal the adsorption mechanism of the carbonates produced by CO₂ adsorption. It was found that the adsorption performance was affected by the irreversible reduction in the number of active sites due to the continuous formation of polydentate carbonate during adsorption and regeneration.