The role of Cu-ion doping in α-MnO2 electrocatalysts for the oxygen reduction reaction in alkaline electrolyte was investigated. Copper doped α-MnO2 nanowires (Cu-α-MnO2) were prepared with varying amounts of Cu2+ using a solvothermal method. The electrocatalytic dataindicates that Cu-α-MnO2 nanowires have higher terminal current densities, enhanced kinetic rate constants, and improved charge transfer resistances that trend with Cu-content, exceeding values attained by α-MnO2 alone. The observed improvement in catalytic behavior correlates with an increase in Mn3+ content for the Cu-α-MnO2 nanowires. The Mn3+/Mn4+ couple is themediator for the rate-limiting redox driven O2-/OH- exchange. It is proposed that O2 adsorbs viaan axial site (the eg orbital on the Mn3+ d4 ion) at the surface, or at edge defects, of the nanowireand that the increase in covalent nature of the nanowire with Cu-ion doping leads to stabilization of O2 adsorbates and faster rates of reduction. This work is applicable to other manganese oxide electrocatalysts and shows for the first time there is a correlation for manganese oxides between electrocatalytic activity for the ORR in alkaline electrolyte and an increase in Mn3+ character of the oxide.
Davis, Danae J., et al. "Role of Cu-Ion Doping in Cu-α-MnO<sub>2</sub> Nanowire Electrocatalysts for the Oxygen Reduction Reaction." Journal of Physical Chemistry. C, vol. 118, no. 31, Jul. 2014. https://doi.org/10.1021/jp5039865
Davis, Danae J., Lambert, Timothy N., Vigil, Julian A., Rodriguez, Mark A., Brumbach, Michael T., Coker, Eric N., & Limmer, Steven J. (2014). Role of Cu-Ion Doping in Cu-α-MnO<sub>2</sub> Nanowire Electrocatalysts for the Oxygen Reduction Reaction. Journal of Physical Chemistry. C, 118(31). https://doi.org/10.1021/jp5039865
Davis, Danae J., Lambert, Timothy N., Vigil, Julian A., et al., "Role of Cu-Ion Doping in Cu-α-MnO<sub>2</sub> Nanowire Electrocatalysts for the Oxygen Reduction Reaction," Journal of Physical Chemistry. C 118, no. 31 (2014), https://doi.org/10.1021/jp5039865
@article{osti_1140890,
author = {Davis, Danae J. and Lambert, Timothy N. and Vigil, Julian A. and Rodriguez, Mark A. and Brumbach, Michael T. and Coker, Eric N. and Limmer, Steven J.},
title = {Role of Cu-Ion Doping in Cu-α-MnO<sub>2</sub> Nanowire Electrocatalysts for the Oxygen Reduction Reaction},
annote = {The role of Cu-ion doping in α-MnO2 electrocatalysts for the oxygen reduction reaction in alkaline electrolyte was investigated. Copper doped α-MnO2 nanowires (Cu-α-MnO2) were prepared with varying amounts of Cu2+ using a solvothermal method. The electrocatalytic dataindicates that Cu-α-MnO2 nanowires have higher terminal current densities, enhanced kinetic rate constants, and improved charge transfer resistances that trend with Cu-content, exceeding values attained by α-MnO2 alone. The observed improvement in catalytic behavior correlates with an increase in Mn3+ content for the Cu-α-MnO2 nanowires. The Mn3+/Mn4+ couple is themediator for the rate-limiting redox driven O2-/OH- exchange. It is proposed that O2 adsorbs viaan axial site (the eg orbital on the Mn3+ d4 ion) at the surface, or at edge defects, of the nanowireand that the increase in covalent nature of the nanowire with Cu-ion doping leads to stabilization of O2 adsorbates and faster rates of reduction. This work is applicable to other manganese oxide electrocatalysts and shows for the first time there is a correlation for manganese oxides between electrocatalytic activity for the ORR in alkaline electrolyte and an increase in Mn3+ character of the oxide.},
doi = {10.1021/jp5039865},
url = {https://www.osti.gov/biblio/1140890},
journal = {Journal of Physical Chemistry. C},
issn = {ISSN 1932-7447},
number = {31},
volume = {118},
place = {United States},
publisher = {American Chemical Society},
year = {2014},
month = {07}}