Trail of sulfur during the desulfurization via reactive adsorption on Ni/ZnO

The reactive adsorption behavior of thiophene on the reduced Ni/ZnO sample was investigated by a combination of theoretical and experimental study. It is widely accepted that Ni is responsible for the sulfur-removal of thiophene to release S-free hydrocarbons. Such surface reaction was simulated by DFT method. It is demonstrated that thiophene is mainly adsorbed as pi-complexation mode over metallic Ni. During desulfurization, the S-Ni bond is formed and the C-S bond is thus split without pre-hydrogenation, resulting in the formation of Ni3S2 phase and S-free C4 olefin which can be further saturated in the presence of H-2. The S-transfer between Ni3S2 and ZnO was monitored by in-situ XRD and STEM with EDS mapping. Two essential features were identified for efficient S-transfer, namely, 1) the H-2 atmosphere, and 2) the two phases are presented with close contact. Based on the acquired information, a general scenario of sulfur trail has been proposed for the desulfurization of thiophene on Ni/ZnO. (C) 2020, Institute of Process Engineering, Chinese Academy of Sciences. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co., Ltd.

Automated summary

The reactive adsorption behavior of thiophene on the reduced Ni/ZnO sample was investigated through theoretical and experimental studies. The sulfur-removal process involves formation of S-Ni bond, leading to cleavage of C-S bond and formation of Ni3S2 phase and S-free C4 olefin. Two essential features for efficient S-transfer were identified as H-2 atmosphere and close contact between the two phases.