PREPARATION OF DIFFERENT POLYOXOMETALATES AND APPLICATION IN ELECTROCHEMICALLY MEDIATED DELIGNIFICATION OF CHEMICAL PULP

摘要

Different polyoxometalates (POMs) were prepared and applied in the electrochemically mediated delignification system (EM) as mediators. The chemical structures and characteristics of these POMs were analyzed as well as the electrochemical properties. The delignification performances of the POM-mediated electrochemical system were discussed. The results showed that different types of POMs had different delignification ratios. When the Ti/RuTiOx was used as anode surface material, the prepared PMO7V5 gave out the highest delignification ratio, 42.0%, among referred POMs and the viscosity loss was only 11.3%. The delignification performance did not have any direct relationship with the cylic voltammogram reversibility of the prepared POM as mediators in this electrochemical delignification system. The type of substituted element in the POM structure affected the electrochemical catalytic capability to some extent.