Synergism in thiophene desulfurization and heavy metals control with CaO

Abstract

The desulfurization of thiophene and heavy metals control have received widespread attention due to the environmental issues, but their interaction mechanism is unclear. In this work, the role of CaO in thiophene desulfurization and heavy metals control was investigated. The CS bond cleavage is the rate-determining step for thiophene desulfurization with the energy barrier of 218.5 kJ/mol on the CaO surface, and the loading of heavy metal clusters Mn₄, Ni₄, and Cu₄ on the CaO(001) surface exhibit high desulfurization activity with energy barriers of 37.2, 44.2 and 112.1 kJ/mol at 973 K. Moreover, the electronic property analysis indicates that the S atom formed by thiophene desulfurization as the active center promotes heavy metals control comparing to the CaO surface. Furthermore, the mutual promotion effect between thiophene desulfurization and heavy metals control was elucidated. The present study broadens the understanding of treating thiophene and heavy metal pollutants in coal and sludge.