Sodium Alginate-Based Carbon Aerogel-Supported ZIF-8-Derived Porous Carbon as an Effective Adsorbent for Methane Gas.

Adsorption natural gas (ANG) is a technology in which natural gas is stored on the surface of porous materials at relatively low pressures, which are promising candidates for adsorption of natural gas. Adsorbent materials with a large surface area and porous structure plays a significant role in the ANG technology, which holds promise in increasing the storage density for natural gas while decreasing the operating pressure. Here, we demonstrate a facile synthetic method for rational construction of a sodium alginate (SA)/ZIF-8 composite carbon aerogel (AZSCA) by incorporating ZIF-8 particles into SA aerogel through a directional freeze-drying method followed by the carbonization process. The structure characterization shows that AZSCA has a hierarchical porous structure, in which the micropores originated from MOF while the mesopores are derived from the three-dimensional network of the aerogel. The experimental results show that AZSCA achieved high methane adsorption of 181 cm·g at 65 bar and 298 K, along with higher isosteric heat of adsorption (Q) throughout the adsorption range. Thus, the combination of MOF powders with aerogel can find potential applications in other gas adsorption.