A theoretical study on sintering of Ni nanoparticles in the anode of solid oxide fuel cell under water vapor environment

Jingxiang Xu, Shandan Bai, Yuji Higuchi, Nobuki Ozawa, Momoji Kubo

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Sintering of Ni particles in the Ni-based anode is a major obstacle to the widespread use of solid oxide fuel cell because the sintering induces the degradation in the anode. The large amount of water vapor in the fuel is known to accelerate the degradation during the operation. However, the detailed accelerated sintering mechanism is unclear. In this study, to clear the accelerated sintering mechanism during the initial stage of the sintering by water vapor, we investigated the adsorption and dissociation of water molecules on the Ni surface as well as the effect of the terminations of O, H, and OH on the interaction between the Ni clusters by density functional theory because the sintering of Ni particles is started by the Ni particles approaching each other due to the attractive interaction between Ni particles at the initial stage. In our adsorption and dissociation calculations, increasing the amount of water vapor facilitates the adsorption of H2O molecule on the Ni surface due to the H-bond interaction. Meanwhile, the activation energy for the dissociation of H2O molecules on the Ni surface is also lowered with increasing the amount of H2O molecules. Then, we calculated the interaction between Ni cluster, and O terminated, OH terminated, and H terminated Ni clusters. We observed that the attractive interaction between Ni cluster and O terminated Ni cluster is larger than that between two Ni clusters in vacuum. Enhancing the attractive interaction is not observed in the H terminated and OH terminated Ni clusters. It indicates that two Ni clusters approaching each other is faster under the water vapor environment than that in vacuum due to the strong attractive interaction caused by the termination of O. Thus, we suggest that the generation of O termination plays an important role in the sintering at the initial stage under the water vapor environment.

Original languageEnglish
Title of host publication16th International Conference on Nanotechnology - IEEE NANO 2016
PublisherInstitute of Electrical and Electronics Engineers Inc.
Pages884-887
Number of pages4
ISBN (Electronic)9781509039142
DOIs
Publication statusPublished - 2016 Nov 21
Event16th IEEE International Conference on Nanotechnology - IEEE NANO 2016 - Sendai, Japan
Duration: 2016 Aug 222016 Aug 25

Publication series

Name16th International Conference on Nanotechnology - IEEE NANO 2016

Other

Other16th IEEE International Conference on Nanotechnology - IEEE NANO 2016
CountryJapan
CitySendai
Period16/8/2216/8/25

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics

Fingerprint Dive into the research topics of 'A theoretical study on sintering of Ni nanoparticles in the anode of solid oxide fuel cell under water vapor environment'. Together they form a unique fingerprint.

Cite this