High-Pressure Hydrogen Storage in Zeolite-Templated Carbon

Abstract

High-pressure hydrogen storage in zeolite-templated carbon (ZTC) was investigated at room temperature (30 °C). Several types of ZTCs with different surface areas and a nitrogen-doped ZTC were prepared. Their hydrogen storage performance at room temperature was examined and the results were compared with those of commercial activated carbons. At pressures below 10 MPa, the hydrogen uptake capacity was simply proportional to specific surface areas of the carbons, and both ZTCs and activated carbon showed almost the same heat of adsorption (6∼8 kJ mol−1). On the other hand, at pressures above 10 MPa, uniform micropores with a diameter of 1.2 nm in ZTCs played a more important role in capacity increase than the specific surface area. As a result, the ZTC with the largest surface area (3370 m2 g−1) exhibited hydrogen uptake as high as 2.2 wt % at 34 MPa. This value is much larger than that of the activated carbon, and such a difference in the capacity between ZTC and activated carbon cannot be explained by the difference in specific surface area alone. Moreover, by loading only a small amount of Pt nanoparticles (ca. 0.2 wt %) onto ZTC, hydrogen uptake capacity was increased from 0.87 to 0.95 wt % at 10 MPa. The increase of hydrogen uptake capacity by Pt loading can be ascribed to hydrogen spillover through the supported Pt nanoparticles to the carbon surface.

Enhanced Hydrogen Dipole Physisorption, Final Report

“…At 6.7 MPa, hydrogen uptake in MSC-30 was 3.1 mmol g -1 , consistent with reported values for MSC-30 to within 0.3 mmol g -1 . 65,66 This value was reproducible upon cycling to well within experimental error, to which we assign an upper bound of ±0.05 mmol g -1 . In Pt-MSC-30, low-pressure data showed a steep initial uptake of hydrogen between 0-0.01 MPa and then a similar constant slope region to MSC-30 between 0.04-2 MPa.…”

“…Template carbonization, among other methods of structural control, has also been explored as a technique to produce carbonaceous materials with exceptionally large specific surface area and finely tuned porosity 120,121,122,123,124,125,126,127 . It was reported in 2009 that a particular class of templated materials, zeolite-templated carbons (ZTCs), exhibits remarkable hydrogen storage capacities at room temperature under high-pressure conditions (10-34 MPa) 122 .…”

Successful functionalization of superporous zeolite templated carbon using aminobenzene acids and electrochemical methods

“…Among others, they are of interest for increasing the electrochemical activity of carbon materials in the oxygen reduction reaction [7], [8]; for increasing the capacitance, rate performance and durability as electrodes of supercapacitors [9]- [11]; for enhancement of gas and liquid adsorption of acid adsorbates [12]; for the preparation of novel heterogeneous catalysts [13], [14] and for the immobilization of bio-molecules [15]. The synthesis of Ncontaining ZTC is done using chemical vapor deposition during its synthesis with which Nspecies are incorporated in the carbon network [16]- [20]; however, it is not possible to control the type of N-species and it inevitably becomes diverse. Post-synthesis modification without structure destruction of ZTC would be a highly desirable method for selective introduction of specific N-containing functional groups.…”

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.…”

“…The pore-size distribution (left) and relative filling (right) of CNS-201 (black), MSC-30 (red), ZTC "P7(2)-H" (blue), and ZTC-3 (purple), calculated by the NLDFT method. 4,5,9,10 It has been proposed that 1.14 nm is the optimal spacing between graphene layers for maximum adsorption uptake of methane. 11,12 The pore-size distribution of ZTC-3 has a mean pore-width close to this value, shown as a gray line in Figure S1.…”