Electrochemical oxygen reduction catalyst
View Patent ↗An electrochemical oxygen reduction catalyst comprising platinum-containing nanoparticles and at least one member selected from the group consisting of a melamine compound, a thiocyanuric acid compound, and a polymer containing the melamine compound or the thiocyanuric acid compound as a monomer is an electrochemical oxygen reduction catalyst having a high oxygen reduction activity (small overvoltage).
1. An electrochemical oxygen reduction catalyst comprising platinum-containing nanoparticles and a polymer containing a melamine compound or a thiocyanuric acid compound as a monomer,
wherein the polymer containing the melamine compound or the thiocyanuric acid compound as a monomer is a polymer containing a repeating unit represented by formula (2):
wherein
Ys may be the same or different, and represent nitrogen or sulfur;
R 4 to R 8 may be the same or different, and represent a divalent group;
R 9 to R 11 may be the same or different, and represent hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, or substituted or unsubstituted aryl;
m1 is 1 or 2, with the proviso that when Y to which R 6 is bonded is sulfur, m1 is 1; and when m1 is 2, two R 6 s may be the same or different and two R 10 s may be the same or different;
m2 and m3 may be the same or different, and represent 0 or 1, with the proviso that Y to which R 7 or R 8 is bonded is sulfur, m2 and m3 are 0; and
OR 9 to OR 11 may be partially or fully eliminated, and cross-linked to the divalent group represented by R 4 to R 8 to form a three-dimensional mesh structure.
2. The electrochemical oxygen reduction catalyst according to claim 1 , wherein the polymer containing the melamine compound or the thiocyanuric acid compound as a monomer is supported on the platinum-containing nanoparticles.
3. The electrochemical oxygen reduction catalyst according to claim 1 , wherein in formula (2), each of R 4 to R 8 is substituted or unsubstituted alkylene, substituted or unsubstituted alkenylene, or substituted or unsubstituted arylene.
4. The electrochemical oxygen reduction catalyst according to claim 1 , which is supported on a conductive carrier.
5. The electrochemical oxygen reduction catalyst according to claim 4 , wherein the conductive carrier is a carbonaceous material.
6. The electrochemical oxygen reduction catalyst according to claim 1 , which is a cathode catalyst for fuel cells.
7. An air electrode for fuel cells or metal-air batteries, using the electrochemical oxygen reduction catalyst according to claim 1 .
8. A fuel cell using the air electrode according to claim 7 as a cathode.
9. A metal-air battery using the air electrode according to claim 7 as a cathode.