Adsorption of CO2 on skeletal cobalt and nickel zirconium phosphates after their treatment with high-frequency hydrogen and argon plasma

Abstract

The effect of the treatment of solid skeletal electrolytes, such as double zirconium phosphates Me_0.5Zr₂(PO₄)₃ (Me = Ni and Co), with high-frequency H₂ and Ar plasma on the adsorption and desorption of CO₂ was examined. It was found that the treatment of cobalt zirconium phosphate with high-frequency H₂ plasma increases its specific surface area, while the pore size is reduced approximately tenfold (from 6.2 to 0.56 nm). Treatment with H₂ and Ar plasma influences the adsorption characteristics of CO₂ in various ways. The activated character of CO₂ adsorption on the initial NiZr and CoZr phosphates remains after their treatment with high-frequency H₂ plasma, while the strength of binding between adsorbate molecules and the surface increases. Treatment with Ar plasma leads to a reduction of CO₂ adsorption with increasing temperature, and the isosteric heats do not depend on the nature of the conductive ion (Co²⁺ or Ni²⁺).