TY - GEN
T1 - Methanol oxidation on Pt(111)/Ru in alkaline media
AU - Spendelow, Jacob S.
AU - Goodpaster, Jason D.
AU - Johnston, Christina M.
AU - Kenis, Paul J A
AU - Wieckowski, Andrzej
PY - 2007
Y1 - 2007
N2 - Dehydrogenation and oxidation of methanol has been studied on well-ordered Pt(111), vicinal Pt(111), and Pt(111)/Ru in alkaline media. Multiple mechanisms of promotion have been identified. Steps with (110) orientation promote methanol dehydrogenation through a geometric effect, while they promote CO oxidation through a change in electronic structure. Adsorbed Ru promotes methanol dehydrogenation through two distinct electronic (ligand) effects: it increases the intrinsic activity of nearby R sites for methanol dehydrogenation, and it decreases the local CO coverage at the active sites even when the overall CO coverage is high. Ru also promotes methanol oxidation through a ligand effect on CO oxidation. The bifunctional effect of Ru is concluded to be much weaker in alkaline media than in acidic media. STM imaging confirms the stability of adsorbed Ru even during extended potential cycling and oxidizing treatments, demonstrating the promising characteristics of Pt/Ru surfaces for fuel cells.
AB - Dehydrogenation and oxidation of methanol has been studied on well-ordered Pt(111), vicinal Pt(111), and Pt(111)/Ru in alkaline media. Multiple mechanisms of promotion have been identified. Steps with (110) orientation promote methanol dehydrogenation through a geometric effect, while they promote CO oxidation through a change in electronic structure. Adsorbed Ru promotes methanol dehydrogenation through two distinct electronic (ligand) effects: it increases the intrinsic activity of nearby R sites for methanol dehydrogenation, and it decreases the local CO coverage at the active sites even when the overall CO coverage is high. Ru also promotes methanol oxidation through a ligand effect on CO oxidation. The bifunctional effect of Ru is concluded to be much weaker in alkaline media than in acidic media. STM imaging confirms the stability of adsorbed Ru even during extended potential cycling and oxidizing treatments, demonstrating the promising characteristics of Pt/Ru surfaces for fuel cells.
UR - http://www.scopus.com/inward/record.url?scp=45249106816&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=45249106816&partnerID=8YFLogxK
U2 - 10.1149/1.2781046
DO - 10.1149/1.2781046
M3 - Conference contribution
AN - SCOPUS:45249106816
SN - 9781566775823
SN - 9781566775670
T3 - ECS Transactions
SP - 1333
EP - 1346
BT - ECS Transactions - 7th Symposium Devoted to Proton Exchange Membrane Fuel Cells
T2 - 7th Symposium Devoted to Proton Exchange Membrane Fuel Cells - 212th ECS Meeting
Y2 - 7 October 2007 through 12 October 2007
ER -
