VOCs adsorption by modified MCM-41 and a new way to recycle adsorbents

MCM-41 was modified by ion exchange of nickel and the adsorptive property was examined using ethylene and n-butane as the representatives of VOCs. The adsorption capacity for n-butane barely changed after modification. The isosteric heat of n-butane adsorption at different coverage was calculated through Clausius-Clapeyron equation and it increased only a little. After modification the maximum adsorption amount for ethylene was 0.59 g g (adsorbent) (-1) at 308 K up to 10(5) Pa. The adsorption capacity was much higher than former reported adsorbents. A possible mechanism was proposed. After thermal treatment, Ni+ ion formed and became the active center of ethylene polymerization. Carbon chain lengths of the final products were limited to the sizes of molecular sieves. Catalytic polymerization and adsorption was considered as a new route for ethylene adsorption. We also declared a new way to recycle the adsorbents by washing with organic solution.