A series of newly developed Mo incorporated Mn-Fe supported on cost-effective mesoporous silica for the reactive adsorption desulfurization process is reported. The performance of the new sorbents was evaluated at 550-750 degrees C over a fixed-bed reactor. 50% 4Mn1Fe-3%Mo/FSM-16 exhibited better desulfurization performanCe at 600 degrees C with a breakthrough sulfur capacity (BSC) of 18.15 g S/100 g sorbent compared to 50% 4Mn1Fe/FSM-16 sorbent. High sulfur capacity (90% of the initial sulfur capacity) of sorbent was maintained after multiple sulfidation-regeneration cycles, which revealed 50% 4Mn1Fe-3%Mo/FSM-16 possessed strong durability. A large amount of elemental sulfur was produced instead of sulfur dioxide (SO2) by a simple regeneration. Moreover, the mechanism of sulfidation-regeneration was confirmed in situ using highly sensitive time-of-flight mass-spectrometry (TOF-MS) for the first time. (C) 2016 Elsevier B.V. All rights reserved.