双核磺化酞菁钴与硫化钠反应的伏安法研究.

PDS desulfurization method has been applied widely because of effectively solving the problem of hydrogen cyanide poisoning. However, the by-products problem is still a hotspot concerned in whole desulfurization field at present. The reaction between binuclear sulfonated phthalocyanine cobalt (hi-CoPc) and sodium sulfide was studied by the cyclic voltammetry in this paper. The results showed that the oxidation reaction of Na2S and Na2Sx on glassy carbon electrode was an irreversible process controlled by concentration diffusion. And the transformation from S2- to S8 was not a one-step process, hut firstly transformed into the intermediate, Sx2-, then further generated S8. Moreover, it was deduced that only 20% of S2- involved in the reaction was converted into S8. Sx2- had two main existing forms within the range from Sx2- to S92-, and their forms might have influences on the formation rate and production amount of S8. Bi-CoPc could he more readily form the coordination complex with OH- in aqueous solution than in carbonate buffer system, hut the redox reaction of Co+/Co2+ is easier in carbonate buffer system than in aqueous system. Meanwhile, S22- was formed firstly in the reaction between bi-CoPc and Na2S, S22- then could transformed into Sx2- with a longer chain, finally formed S8. It was helpful for us to understand the mechanism of PDS desulfurization, and it also had guiding significance for reducing the formation of by-products. [ABSTRACT FROM AUTHOR]