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 p-complexation mode over metallic Ni.During desulfurization,the Se Ni bond is formed and the Ce S bond is thus split without pre-hydrogenation,resulting in the formation of Ni_(3)S_(2)phase and S-free C4 olefin which can be further saturated in the presence of H_(2).The S-transfer between Ni_(3)S_(2)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.