Simultaneous removal of Hg0 and H2S at a high space velocity by water-resistant SnO2/carbon aerogel.

• The 3D structure carbon aerogel with highly dispersed SnO 2 nanoparticles was synthesized. • The sorbent exhibited high Hg0 and H 2 S capture capacities and excellent regeneration performance. • The core-shell structure is beneficial for the resistance to H 2 O. • E-R adsorption mechanism of H 2 S and Hg0 was conformed. A seaweed-templated pathway was developed for the controllable synthesis of SnO 2 /carbon aerogel for the simultaneous removal of Hg0 and H 2 S in natural gases, where the SnO 2 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 Hg0 and H 2 S at a high space velocity of 70,000 h−1 and showed resistance to water. At 5% breakthrough, the Hg0 and H 2 S capture capacities reached as high as 10.37 mg g−1 and 392.23 mg g−1, 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 Hg0 and H 2 S removal at a high space velocity, and the core-shell structure is conducive to prevent poisoning from water. The Hg0 and H 2 S removal over the SnO 2 /aerogel conforms to the E-R mechanism, where H 2 S is first adsorbed and dissociated on the SnO 2 surface to produce active sulfur species, and the adsorbed sulfur then reacts with gaseous Hg0 to form HgS. [ABSTRACT FROM AUTHOR]