(156c) 2017 Topical Conference: Innovations of Green Process Engineering for Sustainable Energy and Environment
AIChE Annual Meeting
2017
2017 Annual Meeting
Topical Conference: Innovations of Green Process Engineering for Sustainable Energy and Environment
Materials and Processes for Thermo-, Electro- and Photo-Chemical Energy Storage
Monday, October 30, 2017 - 1:20pm to 1:45pm
Shoji Hall, Du Sun
Johns Hopkins University
Department of Materials Science and Engineering
206 Maryland Hall 3400 N Charles St. Baltimore, Maryland
The conversion of O2 to H2O is an important fuel cell reaction for the recovery of renewable electricity from chemical fuels.1 To date, most materials utilized for the oxygen reduction reaction (ORR) consist of noble metal rich alloys of the form Pt3X, where X is an earth abundant element.2 Although catalysts of this type have been demonstrated to exhibit high activity for ORR, the 75% Pt loading translates to a relatively modest decrease in the use of Pt. Pd alloy catalysts have been proposed as an alternative to Pt and Pt alloy catalysts; however lower catalytic performance relative to Pt has prevented these materials from attracting considerable attention.3 Recently, we have found that earth abundant metal rich Pd alloys can match Pt for ORR in alkaline media. Pd alloys are promising candidates for replacing Pt in low-temperature fuel cells because 1) Pd is ~1/3 the cost of Pt,3 2) earth-abundant metal rich Pd alloys (< 50% Pd) significantly reduce the amount of noble metal usage. Here, we demonstrate that earth abundant rich alloys of Pd are viable alternatives to Pt for ORR, and structure-property relationships will be discussed.
References
1) Lutz, A. E.; Larson, R. S.; Keller, J. O. Thermodynamic comparison of fuel cells to the Carnot cycle. Int. J. Hydrogen Energy 2002, 27, 1103–1111.
2) Stamenkovic, V.; Mun, B. S.; Mayrhofer, K. J. J.; Ross, P. N.; Markovic, N. M.; Rossmeisl, J.; Greeley, J.; Nørskov, J. K. Changing the activity of electrocatalysts for oxygen reduction by tuning the surface electronic structure. Angew. Chem. Int. Ed. Engl. 2006, 45, 2897–2901.
3) Zhang, L.; Chang, Q.; Chen, H.; Shao, M. Recent advances in palladium-based electrocatalysts for fuel cell reactions and hydrogen evolution reaction. Nano Energy 2016, 29, 198-219.