TY - JOUR
T1 - Combinatorial discovery of bifunctional oxygen reduction - Water oxidation electrocatalysts for regenerative fuel cells
AU - Chen, Guoying
AU - Delafuente, David A.
AU - Sarangapani, S.
AU - Mallouk, Thomas E.
N1 - Funding Information:
We thank the Army Research Office for support of this work under grant DAAH04-94-G-0055, subcontract SA151-298 from Illinois Institute of Technology. DAD thanks the NSF Solid State Chemistry Program for support of his summer research at Penn State. We thank Prof. Eugene Smotkin for helpful discussions about kinetic isotope effects, and for providing a copy of Ref. [42] prior to publication. We also thank Dr. Renxuan Liu for designing the gas diffusion cell used to test bulk catalysts, and Mr. Chad Waraksa for writing the computer program used to analyze current–voltage data. We thank Dr. Rosemary Walsh and the electron microscope facility for the Life Sciences in the Biotechnology Institute at Pennsylvania State University for the use of the scanning electron microscope, and Dr. Jeffrey Shallenberger of the Penn State Materials Characterization Laboratory for obtaining XPS spectra.
PY - 2001/6/15
Y1 - 2001/6/15
N2 - Electrode arrays containing 715 unique combinations of five elements (Pt, Ru, Os, Ir, and Rh) were prepared by borohydride reaction of aqueous metal salts, and were screened for activity as oxygen reduction and water oxidation catalysts. Using a consensus map, catalysts that showed high activity for both reactions and good resistance to anodic corrosion were identified in the Pt-Ru rich region of the Pt-Ru-Ir ternary. The ternary catalyst Pt4.5Ru4Ir0.5 (subscripts indicate atomic ratios) is significantly more active than the previously described Pt1Ir1 bifunctional catalyst for both reactions. While the best ternary catalyst is close to Pt1Ru1 in composition, the latter is unstable with respect to anodic corrosion. A detailed kinetic comparison of anodically stable catalysts Pt4.5Ru4Ir0.5 and Pt1Ir1 showed that the addition of the oxophilic element Ru increases the reaction rate by stabilizing S-O bonds (S ≡ surface atom) and accelerating the oxidative deprotonation of S-OH groups.
AB - Electrode arrays containing 715 unique combinations of five elements (Pt, Ru, Os, Ir, and Rh) were prepared by borohydride reaction of aqueous metal salts, and were screened for activity as oxygen reduction and water oxidation catalysts. Using a consensus map, catalysts that showed high activity for both reactions and good resistance to anodic corrosion were identified in the Pt-Ru rich region of the Pt-Ru-Ir ternary. The ternary catalyst Pt4.5Ru4Ir0.5 (subscripts indicate atomic ratios) is significantly more active than the previously described Pt1Ir1 bifunctional catalyst for both reactions. While the best ternary catalyst is close to Pt1Ru1 in composition, the latter is unstable with respect to anodic corrosion. A detailed kinetic comparison of anodically stable catalysts Pt4.5Ru4Ir0.5 and Pt1Ir1 showed that the addition of the oxophilic element Ru increases the reaction rate by stabilizing S-O bonds (S ≡ surface atom) and accelerating the oxidative deprotonation of S-OH groups.
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U2 - 10.1016/S0920-5861(01)00327-3
DO - 10.1016/S0920-5861(01)00327-3
M3 - Article
AN - SCOPUS:0035875060
SN - 0920-5861
VL - 67
SP - 341
EP - 355
JO - Catalysis Today
JF - Catalysis Today
IS - 4
ER -