Simultaneous removal of Hg and HS at a high space velocity by water-resistant SnO/carbon aerogel.

A seaweed-templated pathway was developed for the controllable synthesis of SnO/carbon aerogel for the simultaneous removal of Hg and HS in natural gases, where the SnO nanoparticles with an outer diameter of 4-20 nm were highly dispersed and conjoined by graphitic carbon, forming a 3D core-shell structure with a developed pore network. The synthesized sorbent performed a complete removal of Hg and HS at a high space velocity of 70,000 h and showed resistance to water. At 5% breakthrough, the Hg and HS capture capacities reached as high as 10.37 mg g and 392.23 mg g, respectively, which are much higher than those of the existing commercial sorbents. More importantly, the spent sorbent could be easily regenerated without significant performance degradation over five cycles. The 3D interconnected macro- and mesopores are beneficial for the Hg and HS removal at a high space velocity, and the core-shell structure is conducive to prevent poisoning from water. The Hg and HS removal over the SnO/aerogel conforms to the E-R mechanism, where HS is first adsorbed and dissociated on the SnO surface to produce active sulfur species, and the adsorbed sulfur then reacts with gaseous Hg to form HgS.