Pore-Scale Modeling of Anode Catalyst Layer Tolerance upon Hydrogen Sulfide Exposure in PEMFC

Yuze Hou,Qing Du,Sebastian Prass,Nada Zamel,Xing Li,Kui Jiao

doi:10.1007/s12678-021-00664-9

Abstract

A pore-scale contamination model is developed to resolve the physicochemical processes in the anode catalyst layer for a deeper insight into the hydrogen sulfide (H2S) contamination mechanism. The present model is based on lattice Boltzmann method (LBM) and a novel iteration algorithm is coupled to overcome the time-scale issue in LBM which can extend its application. The microstructure of CL is stochastically reconstructed considering the presence of carbon, Pt, ionomer, and pores. The proposed model is validated by comparing the experimental data and can accurately predict the effect of H2S contamination on performance with time. The results show that the fuel cell performance is not sensitive to the anode Pt loading under the clean fuel condition as the hydrogen oxidation reaction is easy to activate. However, higher Pt loading can effectively prolong the operation time under the H2S contamination by providing a larger buffer reactive area and a lower H2S concentration condition. Furthermore, the H2S contamination in the fuel gas should be strictly restricted as it directly affects the poisoning rate and significantly affects the operation time.Graphical abstractPhysicochemical processes in the ACL with reactant transport through micro porous layer (MPL) to active Pt sites

Highlights

Proton exchange membrane fuel cell (PEMFC) is a promising energy conversion device, converting the chemical energy of hydrogen and oxygen into electricity through electrochemical reactions [1]
Such phenomenon can be explained by the active nature of hydrogen, which is characterized by a much higher reference local hydrogen oxidation reaction (HOR) rate i0 (b)
The lattice Boltzmann method (LBM)-based pore-scale model is firstly employed to study the fuel cell contamination and coupled with a novel iterate algorithm to overcome the time-scale analysis issue in the original LBM, which is a progress for extending the application of LBM

Summary

Introduction

Proton exchange membrane fuel cell (PEMFC) is a promising energy conversion device, converting the chemical energy of hydrogen and oxygen into electricity through electrochemical reactions [1]. To further increase its competitiveness against the internal combustion (IC) engine and promote the commercialization of fuel cell vehicles, there are still some issues to be tackled to decrease the cost, while increasing the durability [4]. In the state-of-the-art PEMFC, the precious metal platinum (Pt) or Pt-alloys are mostly used as catalyst, contributing to the high cost of the cell [5]. There is a minimum requirement for the Pt loading to ensure stability and durability of the cell against the fuel contamination over its lifetime [6]. The optimization of Pt loading is critically important for the commercialization of fuel cell vehicles and can be achieved by understanding the contamination mechanism along with its dependency on the catalyst layer structure

Methods

Results

Conclusion