Catalyst Degradation Mitigation and Fuel Utilization Enhancement of a Dead-Ended Anode and Cathode Proton Exchange Membrane Fuel Cell with Periodical Oxygen Supply

Abstract

Hydrogen−oxygen proton exchange membrane fuel cells (PEMFCs) have promising military applications. However, carbon corrosion in the catalyst layer induced by water flooding significantly affects the performance and longevity of PEMFCs. In this study, a periodical oxygen supply strategy is proposed to improve water management in PEMFCs. The hydrogen and oxygen utilization reached 99.84 and 98.82%, respectively. The performance degradation rate of a PEMFC with a current density of 600 mA•cm −2 decreased by 45.1% under the proposed strategy. According to morphological results, the thickness degradation rate of the cathode catalyst layer operating in the proposed strategy is generally lower than that in the conventional dead-ended mode, which was mainly due to the irreversible Pt agglomeration, oxidation, and carbon support corrosion, especially in the oxygen outlet area. This work contributes to the engineering application of H 2 /O 2 PEMFCs by providing a deeper understanding of dead-ended behaviors.

Ir/Ni–NiO/CNT composites as effective electrocatalysts for hydrogen oxidation

“…As a kind of alternative power generation device, hydrogen–oxygen fuel cells have received extensive attention due to their high energy conversion efficiency and excellent environmental compatibility. 1–3 At the two ends of the cells, oxygen reduction reaction (ORR) and hydrogen oxidation reaction (HOR) take place. Both ends need catalysts to effectively drive the reduction and oxidation processes.…”

A trinary support of Ni/NiO/C to immobilize Ir nanoclusters for alkaline hydrogen oxidation

“…13,14 Another crucial issue is to carefully adjust the adsorption strength of H ad and OH ad to an optimal level simultaneously. [15][16][17] Supported metal nanoclusters with a particle size less than 3 nm demonstrate improved catalytic efficacy because of their unique geometry, electronic structure, and synergistic interaction with the support material. 16 These nanoclusters also demonstrate high atomic utilization efficiency, exposing more active atoms than their nanoparticle counterparts, thereby providing a multitude of active sites for adsorption and activation of diverse intermediates.…”

“…[15][16][17] Supported metal nanoclusters with a particle size less than 3 nm demonstrate improved catalytic efficacy because of their unique geometry, electronic structure, and synergistic interaction with the support material. 16 These nanoclusters also demonstrate high atomic utilization efficiency, exposing more active atoms than their nanoparticle counterparts, thereby providing a multitude of active sites for adsorption and activation of diverse intermediates. 16,17 The abundant (near-)interface metal atoms within these nanoclusters play a crucial role in optimizing adsorption behaviors across multiple reaction steps.…”

“…16 These nanoclusters also demonstrate high atomic utilization efficiency, exposing more active atoms than their nanoparticle counterparts, thereby providing a multitude of active sites for adsorption and activation of diverse intermediates. 16,17 The abundant (near-)interface metal atoms within these nanoclusters play a crucial role in optimizing adsorption behaviors across multiple reaction steps. This can be effectively modulated by metal-support interactions, including interfacial charge transfer.…”

“…13,14 Another crucial issue is to carefully adjust the adsorption strength of H ad and OH ad to an optimal level simultaneously. 15–17…”