Characterization of hydrogen adsorption in platinum-doped microporous carbon with varied catalytic properties

The effect of the catalytic property of platinum (Pt) on the hydrogen adsorption of activated carbon (AC) via spillover was investigated. The catalytic effect on the hydrogen adsorption via spillover was clearly identified from both adsorption isotherms and adsorption kinetics. Factors, including Pt particle size, Pt loading content and AC nature, in the platinum-doped activated carbon (Pt/AC) were considered in this study. The hydrogen adsorption experiments were performed using a volumetric apparatus at room temperature (RT) and low pressure (∼0.1 MPa). In this study, enhancement factors of 16–145% due to spillover were obtained for the Pt/AC samples because of the difference in the textural properties of AC receptors. The adsorption rate of spilt-over hydrogen is strongly dominated by the Pt surface sites as functions of both crystallite size and deposition type (with or without aggregation). When the Pt surface sites amounted to below 0.011 mmol/g, an insignificant spillover effect was observed in the hydrogen adsorption of Pt/AC.

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► The catalytic property of platinum significantly affected hydrogen spillover performance on the AC receptor.
► The adsorption rate of spilt-over hydrogen is strongly dominated by the number of Pt sites.
► Insignificant spillover effect was observed in Pt sites below 0.011 mmol/g.