Comparative Characterization Study of Microporous Carbons by HRTEM Image Analysis and Gas Adsorption

Abstract

The present work presents a useful comparison of micropore size distributions (MPSDs) obtained from gas adsorption and image analysis of high-resolution transmission electron micrographs. It is shown that the MPSD obtained for a chemical activated carbon is concordant with that obtained from CO2 adsorption. In addition, this technique has allowed us to obtain the MPSD of a carbon molecular sieve (CMS) prepared in our laboratory by a copyrolysis process, which could only be characterized by CO2 adsorption at 273 K (not by N2 adsorption at 77 K due to diffusional problems). The MPSD obtained by high-resolution transmission electron microscopy (HRTEM) for the CMS is wider than that obtained by CO2 adsorption, suggesting that HRTEM is detecting the closed porosity existing in this sample, which is not accessible to gas adsorption. The existence of closed porosity in the CMS is explained considering the preparation method used. Thus, HRTEM combined with image analysis seems to be useful for structural analysis of narrow micropores including closed porosity.

High-Pressure Adsorption of Methane and Carbon Dioxide on Coal

“…These data at high pressures up to 20 MPa allow a more accurate determination of pore volumes and therefore lead to improved characterization. In addition, high-resolution transmission electron microscopy with image analysis can be used to improve the structural analysis of narrow micropores …”

Atomistic modelling insight into the structure of lignite-based activated carbon and benzene sorption behavior

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Preparation and characterization of microporous carbon spheres from high amylose pea maltodextrin

“…The adsorption technique is the most established method to characterize microporous materials. In a recent work, 33 the porosity of the system was investigated using the HRTEM. Thus, the C-LNS was analyzed by HRTEM and the micrograph obtained are reported in Fig.…”