Electrocatalytic behavior of thin Co–Te–O films in oxygen evolution and reduction reactions

The continuing development of Magnéli phase titanium sub-oxides and Ebonex® electrodes

“…Electrocatalytic films of Co-Te-O on Ebonex ® have shown an acceptable performance for oxygen evolution and oxygen reduction reactions -of interest for regenerative fuel cells and batteries [20].…”

“…This is an important feature for longevity of the coating and essential where the toxicity of any electrode dissolu- tion could cause a problem. Active materials may be applied via numerous methods, including thermal decomposition (oxidation) [17], reduction (wet chemistry [18,19] or the use of a H 2 atmosphere [13]) and condensation [20]. Electrodeposition is, perhaps, the most common method used to apply coatings to Magnéli phase materials.…”

Electrocatalysts for bifunctional oxygen/air electrodes

“…Cyclic voltammograms of Co-Te-O a GDE, fresh and thermally treated at different temperatures are given in Fig. 4a [23]. The electrodes have optimal catalyst loading of 0.2 mg cm −2 and atomic ratio R Co/Te = 1.5.…”

“…The oxidation state of the species is Co 2+ , Te 4+ and Te 0 . No changes in the chemical state of the films were found after thermal annealing up to 300 • C ( Table 2) [23] XPS analyses of Co x O y /ZrO 2 layers were performed. The results are summarized in Table 3.…”

“…Among these, cobalt and manganese spinels Co 3 O 4 , M x Co 3−x O 4 (M = Cu, Ni) and Cu x Mn 3−x O 4 are presently being considered as the most promising electrocatalysts in alkaline solutions, because of their relatively high catalytic activity, larger availability and lower cost compared to the noble metals, together with their good corrosion stability [2][3][4][5]. Different methods for electrocatalyst preparation have been proposed: low temperature synthesis using inorganic and organic precursors [6][7][8][9][10]; sol-gel processes [11][12][13]; freeze-drying methods [14]; chemical spray pyrolysis [15]; cathodic sputtering [16]; vacuum evaporation [17][18][19][20][21][22][23], and electrochemical deposition [24][25][26][27][28][29].…”