Raffaele Giuseppe Agostino

Raffaele Giuseppe Agostino

Hydrogen adsorption at high pressure in carbon nanostructures: equilibrium and kinetic properties


H2 is recognized as an ideal energy carrier even though it is not yet commercially used. A major limitation in this direction is the development of an easy and efficient storage process. Scientific research is focusing its efforts in the synthesis and characterization of nanoporous materials for H2 storage. The use of these materials, instead of a H2 storage as a cryogenic liquid or a extremely compressed gas, would resolve the safety problems and reduce the costs of the H2 transport systems. The use of nano-structured materials is based on the use of physical interactions between adsorbent and adsorbate (van der Walls forces) to achieve an easy sorption and release of the gas. However, to reach the H2 density target values indicated by the Department of Energy (DOE) of the United States of America, which sets the gravimetric capacity of hydrogen as 6 weight%, we need the 'tuning' of porous materials (pores size and distribution, specific active surface area), the use of lightweight materials and the functionalization of the pore walls for an effective hydrogen adsorption and release.

 In this framework, the hydrogen adsorption properties of graphite-based materials have been investigated using a Sievert-type volumetric apparatus with which we collect the adsorption isotherms and the relative kinetic behavior. The investigated carbon-based samples have low (activated carbon and cellulose), medium (carbon nanotubes) or high (graphene) specific surface areas. The isotherms were recorded up to 8 MPa and at different temperatures (77 K and ambient temperature). The asymptotic adsorbed H2 amount seems to be mainly related to the specific surface of samples. However, in graphene-based samples at high pressures, we find a selective adsorption allowing the access to the internal surfaces. The results of repetitive adsorption/desorption cycles show the mechanical stability of these materials. Furthermore, different adsorption kinetics are observed according to the samples porosity. In particular, we observed much faster molecular hydrogen diffusion in graphene samples than in the carbon nanotubes and activated carbon/cellulose ones. The equilibrium adsorption properties and the relative kinetics are linked to the morphological and structural properties revealed through the Raman, SEM, XRD and BET techniques.


to the European Conference on Materials and Technologies for Sustainable Growth website.

ECo MaTech will be held in Bled (Slovenia) from 19th to 21st of September 2013.

Eco MaTech is the third edition of a conference that started in 2009. The aim of ECo MaTech is to gather representatives of academic and R&D institutions, industry, governmental agencies and civil society to:

- present their work, ideas and products, 
- increase fruitful exhanges between all the actors involved in sustainable growth technologies, 
- increase the networking with sustainable growth professionals, 
- establish a general discussion platform on sustainable growth.


The conference excursion will take you to the Alpine lake Bohinj (http://www.bohinj.si/en) and waterfall Savica (http://www.burger.si/Slapovi/Bohinj/Savica/uvod_ENG.html).
A farewell party will follow the lake trip by a boat. Comfortable shoes are recommended.

Only cash is exepted for on-site payment.

The poster panels are 1m wide and 2m high. The standrad A0 size posters are recommended (841mm:1189mm).