Activated carbons with appropriate micropore size distribution for hydrogen adsorption

We measured hydrogen storage on five well-known commercial carbon materials (CCMs) and we compared their performances to those obtained on our lab-made activated carbons (ACs). H2 uptake of our lab-made ACs was always higher than that of CCMs of similar SBET, our best AC reached 6 wt.% H2 excess adsorption at 77 K and 4 MPa. We calculated the contribution of four ranges of pores (<0.5 nm; 0.5–0.7 nm, 0.7–2 nm and >2 nm) to the H2 excess adsorption for the 14 carbon materials considered in this study. We clearly demonstrated that: (i) the superiority in H2 excess adsorption of lab-made ACs over the CCMs is related to their pore size distribution; (ii) H2 uptakes higher than 3 wt.% are due to pores with diameter wider than 0.7 nm.

Fitting of the H2 excess adsorption with the pore volume in four width intervalsFigure optionsDownload as PowerPoint slideHighlights
► H2 excess adsorption was fitted with the pore volume in four width intervals.
► H2 uptakes higher than 3 wt.% were reached due to pores wider than 0.7 nm
► Our ACs showed better performances than MAXSORB-3 because of their narrower PSDs.