Modified electrolytic manganese dioxide (MEMD) for oxygen generation in alkaline medium
- 323 Downloads
Undoubtedly, hydrogen will play an important role in the energy sector in the near future, in particular, as a fuel for transportation. However, electrolytic hydrogen generation is energy intensive and the means to save energy have been widely studied, as for example, the use of proton exchange membranes to minimize the voltage drop across the electrolyte. This research focuses in developing inexpensive alternative anode materials for oxygen generation in order to substitute expensive conventional anodes such as dimensionally stable anodes (DSA®). The geometric and electronic factors of the starting ‘electrolytic manganese dioxide (EMD) material’ are modified to enhance its electrochemical activity toward the oxygen evolution reaction. This has been achieved while using different dopants as additives during electrodeposition of MnO2. The linear voltammetry and electrochemical impedance spectroscopy (EIS) analysis showed an increase in the surface area for the modified EMD (MEMD). X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) associated with elemental analysis (energy-dispersive X-ray spectroscopy (EDS)) illustrate a change in the oxygen composition and acidity which is correlated to the changes in electronic factor of the EMD. These results elucidate the improvement in overpotential observed for MEMDs when compared to that of DSA® at the current density of 100 mA cm−2.
KeywordsEMD Oxygen evolution Electrochemistry Hydrogen
The authors would like to thank AINSE Ltd. for providing financial assistance (Award No. ALNGRA12020/10366 and AINSE Post Graduate Research Award 10595) to enable the work on the catalyst surfaces. We would also like to acknowledge the technological support from Australian Nuclear Science and Technology Organization (ANSTO) and also the global R&D Centers Program of National Research Foundation (NRF) of Korea, funded by Ministry of Science, ICT and Future Planning (MSIP) at Korean Institute of Geoscience and Mineral Resources (KIGAM), for instrument time.
- 2.Bockris JOM (1975) The solar-hydrogen alternative. Australia & New Zealand Book Co Pty Ltd, BrookvaleGoogle Scholar
- 5.Bockris JOM, Reddy AKN, Gamboa-Aldeco M (2000) Modern electrochemistry, vol 2A, 2nd edn. Kluwer Academic/Plenum, New YorkGoogle Scholar
- 15.Krasilshchikov AI (1963) Intermediate stages of anodic oxygen evolution. Russ J Phys Chem 37:273Google Scholar
- 16.Kobussen AGC, Broers GHJ (1980) The oxygen evolution on La0.5Ba0.5CoO3: theoretical impedance behaviour for a multi-step mechanism involving two adsorbates. J Electroanal Chem Interfacial Electrochem 126(1–3):221–240Google Scholar
- 18.O’Grady W, Iwakura C, Huang J, Yeager E (1974) Ruthenium oxide catalysts for the oxygen electrode. In: Breiter MW (ed) Proc Symp Electrocatal pp 286-302Google Scholar
- 19.O’Grady WE, Iwakura C, Yeager E (1976) Oxygen electrocatalysts for life support systems. Am Soc Mech Eng 1976 (76-ENAs-37):11Google Scholar
- 23.Bockris JOM (1956) Kinetics of activation-controlled consecutive electrochemical reactions: anodic evolution of oxygen. J Chem Phys 817–827Google Scholar
- 27.Lasia A (1999) Electrochemical impedance spectroscopy and its applications. In: Conway BE, Bockris J, White RE (eds) Modern aspects of electrochemistry, vol 32. Kluwer Academic/Plenum, New York, pp 143–248Google Scholar
- 31.Simon DE, Morton RW, Gislason JJ (2004) A close look at electrolytic manganese dioxide (EMD) and the γ-MnO2 & ε-MnO2 phases using Rietveld modeling. Adv X-ray Anal 47:267–280Google Scholar
- 36.Nesbitt HW, Banerjee D (1998) Interpretation of XPS Mn(2p) spectra on Mn oxyhydroxides and constraints on the mechanism of MnO2 precipitation. Am Mineral 83:305–315Google Scholar