Titanium Positive Plate Manufacturing Process and Denitrification Mechanism
Prepared a electrode with high concentration and strong active oxidizing property which used titanium as anode’s substrate material, used gradient method the anode surface was coated with a definite ratio RuO2、TiO2、IrO2、SnO2、Ga and Ce in order to extend the operational life span. Use scanning electron microscope to present the surface property, the result shows that the surface coat of self-made titanium positive plate is densification and well-distributed which has good catalytic activity and reaction stability, meanwhile the surface coated with metallic oxides has less and short cracks which can extend the useful life. Through the electrochemistry property detection by electrochemistry workstation, Tafel curve shows that the chlorine precipitation potential is 1.41V which is just a little higher than the standard potential 1.36v of Cl- reacting to form Cl2, meanwhile lower than the oxygen precipitation potential, these shows that the plate has good electro-catalysis property and selectivity. The self-made experimental setup includes four parts as direct supply, reactive tank, electrode, collecting bottle. Prepared solution with deionized water and analytical pure agents with NH4Cl and NaCl, with draining water method collecting the electro-catalysis gas and gas chromatographic analysis shows the main component includes N2 62.73%, O2 21.47%，H2 13.95%，Cl2 1.85%, meanwhile analysis the trends of nitrogen forms concentration, chloridion concentration and pH by electrolysis time, concluding that the indirect oxidation is dominant process during electrochemistry, active substrate OCl- is the principal oxidation. The electrolyte pH keeps range between 7.5 and 9.5 which is favorable to free ammonia forming that can be directly electrochemical oxidized, meanwhile is disadvantage of free chlorine forming that can keep cyclic utilization in solution.
Xianghua Liu, Zhengyi Jiang and Jingtao Han
L. P. Zhang et al., "Titanium Positive Plate Manufacturing Process and Denitrification Mechanism", Advanced Materials Research, Vols. 148-149, pp. 668-673, 2011