Catalytic effect of phosphorus on SO2 oxidation in liquid phase: Experimental and theoretical studies

In this work, experimental and theoretical methods were used to investigate the catalytic effect of P-4 on SO2 oxidation in the liquid phase. Experimental results indicated that P-4 promoted SO2 oxidation by generating O-3. Meanwhile, the desulfurization efficiency was inhibited by H3PO4. Theoretical results indicated that the preferential adsorption of O-2 over P-4 was beneficial to the formation of O-3. Furthermore, the free O atom was a key role in forming O-3 and P4O due to the oxidation ability of O-3 and P4O for SO2. In the liquid phase desulfurization process, O-2 and SO2 were firstly dissolved into the liquid phase. Then, O-3 and P4O were generated from the interaction of O-2 and P-4. Next, SO2 moved close to O-3 and was oxidized into SO3 without H3PO4. Finally, SO3 was hydrated into H2SO4 with H3PO4. The oxidation of SO2 by O-3 without H3PO4 was the rate-determining step in the desulfurization process. H3PO4 slightly promoted the hydration reaction of SO3 but inhibited the oxidation of SO2. In general, the formation of H(3)PO(4 )consumed P-4 and led to the decreasing desulfurization efficiency.

Automated summary

The study found that P-4 promoted the oxidation of SO2 by generating O-3, while H3PO4 inhibited the desulfurization efficiency. In the liquid phase desulfurization process, the oxidation reaction of SO2 by O-3 was identified as the rate-determining step.