A theoretical investigation on the potential of copper- and zinc-doped nanotubes as catalysts for the oxidation of SO2 (SO2+1/2O2 → SO3) and CO (CO+1/2O2 → CO2)

The oxidation of sulfur dioxide and carbon monoxide on the surface of metal-doped nanotube catalysts is investigated, in particular on Cu-doped carbon nanotube (CNT), Cu-doped boron nitride nanotube (BNNT), Zn-doped CNT, and Zn-doped BNNT via the Eley-Rideal and Langmuir-Hinshelwood mechanisms. The reaction energies and barrier energies for all the reaction steps involved in the oxidation of SO2 and carbon monoxide on the studied catalysts are calculated and compared. A suitable mechanism with lower barrier energies and higher reaction energies for the oxidation of sulfur dioxide and carbon monoxide is considered. The results show that the barrier energies for the reaction steps in the oxidation of sulfur dioxide and carbon monoxide molecules are lower on Cu-doped BNNT and Zn-doped BNNT compared with Cu-doped CNT and Zn-doped CNT, respectively. Finally, the Cu-doped CNT and Zn-doped CNT catalysts are proposed for the oxidation of sulfur dioxide and carbon monoxide molecules with suitable performance.