Atypical hydrogen uptake on chemically-activated, ultramicroporous carbon

作者：Bhat Vinay V; Contescu Cristian I^*; Gallego Nidia C; Baker Frederick S

来源：Carbon, 2010, 48(5): 1331-1340.

DOI：10.1016/j.carbon.2009.12.001

Hydrogen adsorption on ultramicroporous carbon was investigated at near-ambient temperatures using volumetric and gravimetric methods The results showed that the main process, physisorption, is accompanied by a slow process of different nature, that causes slow uptake at high pressures and hysteresis on desorption The combined result is unusually high levels of hydrogen uptake at near-ambient temperatures and pressures (e g up to 0 8 wt % at 25 degrees C and 2 MPa). The heat of adsorption corresponding to the slow process leading to high uptake (17-20 kJ/mol) is higher than usually reported for carbon materials, the adsorption kinetics is slow, and the isotherms exhibit pronounced hysteresis These unusual properties were attributed to contributions from polarization-enhanced physisorption induced by traces of alkali metals residual from chemical activation The results support the hypothesis that polarization-induced physisorption

• 出版日期2010-4