A strategy to promote hydrogen storage performance of porous carbon materials: Enriching micropore structure through mechanical pressure-assisted activation

Porous carbon materials (PCMs) with high specific surface area (SSA) exhibit significant potential for hydrogen storage applications but are severely limited due to the weak interactions of H 2 . In this work, polyvinylpyrrolidone (PVP) was employed to prepare PCMs with ultra-high SSA and high micropore ratio through applying mechanical pressure before activation. This approach resulted in an SSA exceeding 3100 m 2 /g and a maximum S BET /S Micro ratio above 90%. The increased microporosity significantly improved hydrogen storage performance, with a 62% increase in hydrogen uptake capacity per SSA at 77 K and 50 bar-H 2 , suggesting the strengthened interaction between PCMs and H 2 . This is further supported by the increased isosteric heat of hydrogen adsorption (Q st ) values from 6.93 to 7.56 kJ/mol at near-zero hydrogen coverage, with S Micro /S BET increasing from 75.86% to 90.83%. Moreover, the increased microporosity enhances the volumetric and usable hydrogen storage capacity. Remarkably, the PCM with 84.35% microporosity and high SSA of 3116.58 m 2 /g exhibits a hydrogen uptake of 6.10 wt% (26.47 g/L) at 77 K under 50 bar-H 2 , and retains 1.26 wt% (5.52 g/L) even at 298 K and 130 bar-H 2 . This study provides a valuable reference for the large-scale preparation of PCMs with high SSA and microporosity for hydrogen storage.