Thermal and structural stability of microporous natural clinoptilolite zeolite

Thermal treatment of zeolites prior to their use as adsorbents is needed to remove adsorbed water from zeolite pores, increasing porosity and surface area without inducing structural deterioration. Here, natural zeolite cli-noptilolite (CLI) was thermally treated at 378-1073 K in air atmosphere. Porosity and structural changes after treatments at particular temperatures were investigated with N-2 adsorption at 77 K, Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD). Brunauer, Emmett and Teller (BET) surface area reached 60 m(2) g(-1) and alpha S surface area reached 80 m(2) g(-1) after thermal treatment at 473 K due to the evolution of water as evidenced with FTIR spectroscopy. Monoclinic crystal structure of the CLI zeolite was preserved after thermal treatment at similar to 873 K as indicated with XRD analysis. The CLI zeolite are structurally stable at similar to 873 K, reaching the highest specific surface area at 473 K, thus being promising for future adsorbent applications.

Automated summary

Thermal treatment can increase the porosity and surface area of zeolites without causing structural deterioration. The study found that the specific surface area of CLI zeolite significantly increased after thermal treatment at 473 K, while maintaining its structural stability.