摘要
Strontium chloride (SrCl2) as ammonia (NH3) carriers has been widely exploited due to its high ammonia uptake capacity and low energy penalty for ammonia release. However, the dramatic volume swing during absorption–desorption cycles, from SrCl2 to Sr(NH3)8Cl2 to SrCl2, imposes a challenge to structure SrCl2 for ammonia storage applications. Herein, a novel porous SrCl2 structure with SrCl2 loading up to 96 wt%, scaffolded by reduced graphene oxide (rGO) networks is reported. The optimized porous SrCl2-rGO composite with 80 wt% SrCl2 loading maintains the macro- and micro-structure accommodating the volume swing during ammonia absorption–desorption cycles without disintegration, whereas structured SrCl2 pellets disintegrates directly after the first cycle of NH3 absorption. The structured porous 80 wt% SrCl2-rGO composite demonstrates rapid absorption–desorption kinetics, 140% faster in absorption and 540% faster in desorption compared with pure SrCl2 pellet. The enhancement of the surface area and the presence of SrCl2 particles in the pores of rGO networks result in a robust and stable structure offering rapid ammonia absorption–desorption kinetics while countermining the volume swing by self-adjusting “breathing.”
