Investigations into
Sulfur Poisoning Mechanisms in Solid-State Oxide Fuel Cells
Using Quantum-Chemical Computations
EMSL Project ID
19398
Abstract
The objective of the proposed study is to gain a fundamental understanding of the sulfur poisoning processes in solid oxide fuel cells due to sulfur-containing impurities in the fuel. First, the interfacial reactions of the sulfur-containing impurities in a hydrogen fuel on the anode surfaces and triple-phase boundary will be performed by first-principles calculations. The computed results will then be employed for the kinetic study to resolve the reaction mechanism and elucidate the potential energy surface of the sulfur poisoning process. Second, considering the temperature of the system and the partial pressure of the sulfur contaminant, comprehensive thermodynamic diagrams of various sulfides on the surfaces can be constructed through the calculation of the free energy. Furthermore, new materials with higher sulfur tolerance will also be examined to improve the resistance to sulfur poisoning. The ultimate objective of the proposed study is to gain a profound scientific understanding of SOFC degradation at the molecular level upon exposure to a sulfur-containing fuel. These electrode reactions are very complex, especially those occurring at the 3-phase boundaries between a gas, a mixed conductor, and an electrolyte like yttria-stablized zirconia (YSZ). Understanding the mechanism of these reactions in an SOFC is vital to achieving intelligent design of novel materials for a new generation of fuel cells.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2006-07-21
End Date
2008-12-04
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members
Related Publications
Choi Y, DS Mebane, JH Wang, and M Liu. 2009. "Continuum and Quantum-Chemical Modeling of Oxygen Reduction on the Cathode in a Solid Oxide Fuel Cell." Topics in Catalysis 46(3-4):386-401. doi:10.1007/s11244-007-9011-x
Wang JH, and M Liu. 2007. "Computational Study of Sulfur–nickel Interactions: A New S–Ni Phase Diagram." Electrochemistry Communications 9(9):2212-2217. doi:10.1016/j.elecom.2007.06.022
Wang JH, and M Liu. 2010. "Surface Regeneration of Sulfur-poisoned Ni Surfaces Under SOFC Operation Conditions Predicted by First-principles-based Thermodynamic Calculations." , Pacific Northwest National Laboratory, Richland, WA. doi:10.1016/j.jpowsour.2007.10.025
Wang JH, Y Choi, and M Liu. 2010. "Quantum Chemical Calculations of Surface and Interfacial Reactions in Solid Oxide Fuel Cells." Chapter 14 in Quantum Chemical Calculations of Surfaces and Interfaces of Materials, ed. Vladimir A. Basiuk and Piero Ugliengo, p. 289–304.
Wang JH, Z Cheng, JL Bredas, and M Liu. 2010. "Electronic and vibrational properties of nickel sulfides from first principles." doi:10.1063/1.2801985