Abstract:

Microporous structure is crucial to the properties and applications of porous carbon materials, but how to modulate it by an ion catalyst faces a complex situation. Here, a uniform porous carbon was obtained from phenolic resin/ethylene glycol through polymerization-induced phase separation (PIPS) method. Meanwhile, the influences of Zn²⁺ content and curing temperature on the microporous structure of porous carbon were studied. Regarding curing temperature, it was observed that the stability of porous carbon decreased with increasing temperature, adversely affecting the uniformity of microporous structure. At a curing temperature of 90 ℃, porosity, mean pore size, and median pore size of the porous carbon varied from 40.22% to 70.38%, 49.8 nm to 279.4 nm, and 107.2 nm to 343.0 nm, respectively. Concerning Zn²⁺ content, an initial increase was noted in porosity, median pore size and average pore size of the porous carbon with rising Zn²⁺ content, followed by a decrease. Specifically, with 1.5% (in mass) Zn²⁺, the maximum pore size and porosity reached 343.0 nm and (70.38±0.37)%, respectively. These findings show that addition of Zn²⁺ increases the curing degree and backbone polymerization, which may be attributed to a reduction in the reaction barrier for interstitial substitution of phenol structures. However, excessive Zn²⁺ content leads to high polymerization levels in the resin mixture, impeding volatilization of the alcohol-rich phase and thus degrading the pore structure. In addition, introduction of Zn²⁺ promotes graphitization, resulting in a more pronounced carbon skeleton than that of non-introduced sample. This research provides a theoretical basis for modulating the microstructure of porous carbon materials and preparation of structural carbide ceramics.

Key words: porous carbon, polymerization-induced phase separation method, Zn²⁺ catalyst, catalytic mechanism, pore structure