A genetically optimized kinetic model for ethanol electro-oxidation on Pt-based binary catalysts used in direct ethanol fuel cells Articles uri icon

publication date

  • September 2017

start page

  • 341

end page

  • 355

volume

  • 363

International Standard Serial Number (ISSN)

  • 0378-7753

Electronic International Standard Serial Number (EISSN)

  • 1873-2755

abstract

  • A one-dimensional model is proposed for the anode of a liquid-feed direct ethanol fuel cell. The complex kinetics of the ethanol electro-oxidation reaction is described using a multi-step reaction mechanism that considers free and adsorbed intermediate species on Pt-based binary catalysts. The adsorbed species are modeled using coverage factors to account for the blockage of the active reaction sites on the catalyst surface. The reaction rates are described by Butler-Volmer equations that are coupled to a one-dimensional mass transport model, which incorporates the effect of ethanol and acetaldehyde crossover. The proposed kinetic model circumvents the acetaldehyde bottleneck effect observed in previous studies by incorporating CH3CHOHads among the adsorbed intermediates. A multi-objetive genetic algorithm is used to determine the reaction constants using anode polarization and product selectivity data obtained from the literature. By adjusting the reaction constants using the methodology developed here, different catalyst layers could be modeled and their selectivities could be successfully reproduced. (C) 2017 Elsevier B.V. All rights reserved.

subjects

  • Mechanical Engineering
  • Renewable Energies

keywords

  • defc modeling; ethanol electro-oxidation; reaction mechanism; coverage factors; product selectivity; genetic optimization