Precisely capture trace ammonia from fuel cell system over ionic liquid grafted hierarchically porous carbons

A solid ionic liquid adsorbent, obtained by grafting [C3N][SO4H] onto porous carbon was reported. Characterizations including IR, XPS and TEM provided the structural information of the sulfonic acid groups on the porous carbon matrix, affirming the feasibility of this synthesis method. The results elucidated the synergy between the sulfonic acid groups and the pore structure of porous carbon, resulting in substantial enhancements in both ammonia adsorption capacity and adsorption selectivity. Moreover, this absorbent exhibited the ability to capture minute concentrations of ammonia below 0.1 ppm with great efficacy and excellent regeneration property within 8 cycles. This simple grafting and acid activation technique proffers a valuable tool for designing adsorbent of trace ammonia within ammonia-hydrogen fuel cells.