Rational Design and Engineering of Metal-based Nanomaterials for Multifunctional Electrocatalysis

• Author / Creator

  Li, Hangxuan

• Multifunctional electrocatalysis plays an important role in renewable energy conversion, supporting a variety of clean energy devices such as fuel cells, electrolyzers, and metal-air batteries. Hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR) are the most significant electrocatalytic reactions that have attracted great research interest. However, several challenges still exist in the design and fabrication of electrocatalysts in terms of cost, performance, and stability.
  To address these issues, I attempt to tackle the problems of both cost and electrocatalytic performance, and also fabricate the multifunctional catalysts for different half reactions. Based on the literature review of recent works, I successfully fabricated the transition metal-based nanomaterials supported on the nickel foam and it shows bifunctional electrocatalytic performance for HER and OER.
  Chapter 1 is a literature review on novel Pd-based and transition metal-based nanomaterials for multifunctional ORR/OER/HER electrocatalysis in both acidic and alkaline media. The mechanism of electrocatalytic reactions and the challenges of both Pd-based and transition metal-based catalysts are demonstrated. Effective strategies such as alloying design, single-atom catalyst design, interface engineering, and heterojunction construction are summarized.
  Chapter 2 clarifies the objectives and experimental design based on the literature review.
  Chapter 3 is an experimental section for the design and fabrication of transition metal-based heterogeneous structural Co2P-Ni3S2 hollow nanowires supported on nickel foam (Co2P-Ni3S2/NF). Owing to the multiple active sites provided by transition metal compounds, the large surface area of the unique hollow nanowire morphology, and the synergistic effect of Co2P-Ni3S2 heterostructure interfaces, the as-prepared catalyst exhibits remarkable bifunctional HER/OER performance. It requires ultralow overpotentials of 110, 164 mV for HER and 331.7, 358.3 mV for OER at large current densities of 100, 500 mA cm-2 in alkaline medium, respectively. Impressively, the two-electrode electrolyzer assembled by Co2P-Ni3S2/NF displays a cell voltage of 1.54 V at 10 mA cm-2 and operates stably over 24 h at 100 mA cm-2.
  Chapter 4 briefly summarizes recent progress in the literature review and experimental results in the first three chapters, analyzes the existing challenges, and proposes future prospects.

• Subjects / Keywords

  • Multifunctional electrocatalysis
  • Nanomaterials
  • Water splitting

• Graduation date

  Fall 2023

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-xera-fc63

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.