Enhanced Hydrogen Storage Capacity of High Surface Area Zeolite-like Carbon Materials

Abstract

We report the synthesis of zeolite-like carbon materials that exhibit well-resolved powder XRD patterns and very high surface area. The zeolite-like carbons are prepared via chemical vapor deposition (CVD) at 800 or 850 degrees C using zeolite beta as solid template and acetonitrile as carbon precursor. The zeolite-like structural ordering of the carbon materials is indicated by powder XRD patterns with at least two well-resolved diffraction peaks and TEM images that reveal well-ordered micropore channels. The carbons possess surface area of up to 3200 m2/g and pore volume of up to 2.41 cm3/g. A significant proportion of the porosity in the carbons (up to 76% and 56% for surface area and pore volume, respectively) is from micropores. Both TEM and nitrogen sorption data indicate that porosity is dominated by pores of size 0.6-0.8 nm. The carbon materials exhibit enhanced (and reversible) hydrogen storage capacity, with measured uptake of up to 6.9 wt % and estimated maximum of 8.33 wt % at -196 degrees C and 20 bar. At 1 bar, hydrogen uptake capacity as high as 2.6 wt % is achieved. Isosteric heat of adsorption of 8.2 kJ/mol indicates a favorable interaction between hydrogen and the surface of the carbons. The hydrogen uptake capacity observed for the zeolite-like carbon materials is among the highest ever reported for carbon (activated carbon, mesoporous carbon, CNTs) or any other (MOFs, zeolites) porous material.

Large surface area sucrose-based carbons via template-assisted routes: Preparation, microstructure, and hydrogen adsorption properties

“…1c). A sharp peak at around 18 • in Cs-90 is the first time for observations and we speculatively believe that it maybe arise from other turbostaratic carbon contaminants [17,38]. In addition, the presence of USY zeolites in carbonization process can definitely inhibit the graphitization.…”

“…Representative SEM pictures for USY zeolite template and sucrose-based carbons. carbons derived from zeolite with other kinds of precursors [4,38,42]. Comparatively, Cs-90 and UCs-90-2 show well sheetgraphite-like structures with large interparticle voids on micrometer scale.…”

Superhydrophobic Activated Carbon‐Coated Sponges for Separation and Absorption

“…Brunauer-Emmett-Teller (BET) surface areas were calculated to be 1975 and 1222 m 2 g À1 for AK 1 and activated carbon, respectively. According to a previous study, [24,28] KOH activation generates micropores, which in turn leads to an increase in specific surface areas of carbon materials. [29,30] In that study, the specific surface area of AK 1 was enhanced greatly after KOH treatment.…”

“…Both activated carbon and AK 1 exhibit broad and low intensity peaks at around 238, which are attributed to the (002) Bragg diffraction from turbostratic carbon. [24] An empirical parameter (R), which is described as the ratio of the height of the (002) Bragg peak to the background (Figure 1 b), was used to measure the number of carbon sheets arranged as single layers. [25] For activated carbon and AK 1 , the values of R were calculated to be 4.5 and 3.5, respectively.…”

Anomalous Isosteric Enthalpy of Adsorption of Methane on Zeolite-Templated Carbon

“…4 In summary, it was found that ZTC-3 has chemical properties similar to other ZTCs (being predominantly sp 2 hybridized carbon) and has very high template fidelity, having the structural traits of the best reported examples. 5,6 Its hydrogen adsorption properties are among the highest of reported carbonaceous materials, but are proportional to surface area between 77-298 K as for other carbons. The narrow pore-size distribution centered at 1.2 nm is not optimized for hydrogen adsorption.…”