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Graphical abstract Highlights • A facile method was developed to synthesize regenerable and H 2 O resistance sorbent for Hg0 removal. • The Ag nanoparticles were successively confined inside the mesoporous channels of MCM-41 molecule sieve. • The nanoconfinement effect is conducive to excellent Hg0 removal performance and regeneration ability. • The high hydrophobicity of Ag/MCM-41 is beneficial for the resistance to H 2 O. Abstract A facile passivation treatment and amino functionalized method was developed for controllable synthesis of effective and water-resistant Ag/MCM-41 composite sorbent for Hg0 removal in natural gas. The Ag nanoparticles were successively confined inside the mesoporous channels of MCM-41 molecule sieve with an average diameter of 3 nm. The synthesized sorbent was found to achieve a complete removal of Hg0 at high space velocity of 50,000 h−1 in ambient temperature. At 5% breakthrough, the Hg0 capture capacity of 1% (wt%) silver loaded Ag/MCM-41 was as high as 6.64 mg·g−1, which is much higher than the sample of Ag loaded outside of the pore channels (S-Ag/MCM-41) and other existing commercial sorbents. The H 2 O has negligible inhibitory effect on Hg0 removal performance of Ag/MCM-41. In addition, the spent Ag/MCM-41 could be easily regenerated without significant performance degradation over five cycles. We considered the high Hg0 capture efficiency, large adsorption capacity and excellent regeneration performance of Ag/MCM-41 are contributed to the nanoconfinement effect of mesoporous channels of MCM-41 molecule sieve which effectively prevented the growth and agglomeration of Ag nanoparticles. The good hydrophobicity of Ag/MCM-41 is beneficial for the high resistance to H 2 O. This work represents a giant step toward the preparation of effective sorbent for practical applications of Hg0 removal in natural gas. [ABSTRACT FROM AUTHOR]

• A regenerable and H 2 S resistance Hg0 removal sorbent was synthesized using fulvic acid. • The Ag nanoparticles were confined and embedded in the carbon nanosheets. • The special core-shell structure of Ag/Fvs is beneficial for the tolerance to H 2 S. • The nanoconfinement of carbon layer is conducive to regeneration performance. The migration and agglomeration of Ag nanoparticles during high temperature regeneration processes were generally considered the key contributor for the decreasing of Hg0 removal performance over Ag-based sorbents. In this work, a complexation pathway was developed for controllable synthesis of Ag loaded carbon nanosheet (Ag/Fvs) using fulvic acid as template and carbon source. The elemental Ag nanoparticles were highly dispersed and embedded in the carbon nanosheet with an average diameter of 7.12 nm and formed a special core-shell structure. The synthesized sorbent achieved a complete Hg0 removal in H 2 S containing natural gas at ambient temperature. At 1% breakthrough, the Hg0 capture capacity of Ag/Fvs was as high as 1.36 mg·g−1, which is much higher than the sample prepared by traditional impregnation method (I-Ag/Fvs, 0.98 mg·g−1) and other existing commercial sorbents. More importantly, the spent Ag/Fvs could be easily regenerated by thermal treating process, its Hg0 capture capacity only slightly decreased by 5.8% after 4 cycles. We considered the carbon layer prevented Ag nanoparticles from poisoning by H 2 S, and more active sulfur sites for Hg0 capture could be formed on porous carbon nanosheets by chemical adsorption of H 2 S, which is beneficial for the strong tolerance to H 2 S. The excellent regeneration performance of Ag/Fvs mainly attributed to the nanoconfinement of carbon layer, which is conducive to prevent the agglomeration of Ag nanoparticles during high temperature regeneration processes. This work represented a practical and efficient pathway to utilize the cheap fulvic acid for applications of Hg0 removal in H 2 S containing natural gas. [ABSTRACT FROM AUTHOR]