ISSN:
1013-9826
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
The activity of electrochemical oxygen reduction (EOR) for the pyrochlores Ln2Ru2-XO7-δ(Ln=Pr,Nd,Sm) [LnR] were examined in 0.1 M KOH aqueous solution at 70oC. The onset voltage(Vo) of the oxygen reduction current and the efficiency (E4) of 4-electron reduction of oxygen wereevaluated by semi-steady state voltammetry with rotating ring-disk electrodes. PrR with the highestEOR activity showed Vo = ~ 0.85 V vs. reversible hydrogen electrode and E4 values above 80 %.Their Vo and E4 values show that LnR containing Ln with a smaller atomic number has a higherEOR activity, i.e. the order of the activity is PrR 〉 NdR 〉 SmR. This was in good agreement withthat of the lattice parameters of LnR. These results indicate that the EOR activity of LnR dependson the kind and/or the size of the lanthanide metal ion on the A-site. PrR and NdR exhibited higherE4 values than known excellent Pb2Ru2O7-δ electrocatalyst containing toxic Pb
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/55/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.350.167.pdf
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