LDH-based efficient electrocatalysts for water electrolysis

• Main Author: Ma, Lingjie
• Other Authors: Fan Hongjin
• Format: Final Year Project
• Language: English
• Published: 2015
• Subjects: DRNTU::Engineering::Materials::Testing of materials
• Online Access: http://hdl.handle.net/10356/64762
• Institution: Nanyang Technological University

For decades, people have been seeking clean energy sources after realizing the potential hazards of the global warming. As a perfect fuel with high calorific value, hydrogen provides us with no emission of pollutants or greenhouse gases that draws global attention as the fuel of future. Among all practical methods of hydrogen generation, one of the easiest ways to produce hydrogen is through electrolysis of water. However, about 95%of the hydrogen produced in traditional industry is from steam reforming from hydrocarbons due to the lower cost comparing to electrolysis1. Since water resource on earth is too abundant to exhaust, mass production of hydrogen through water electrolysis with lower cost has become the goal of many researchers. To realize the commercial requirements from hydrogen industry, mature techniques with high efficiency for water electrolysis have been developed for years, such as alkaline water electrolysis and polymer electrolyte membrane electrolysis. The main challenge people are facing is the cost of electrodes, since the traditional electrodes are made of precious metal such as Platinum electrodes for hydrogen evolution and Iridium oxide electrodes for oxygen evolution. Thus, how to provide with more commercial catalytic electrodes has been raised as an attractive topic among scientists. Oxygen evolution reaction (OER) is the half reaction of the water electrolysis taking place on the anode. Today, electrodes made of alloys consisting of nickel, iron and chromium are often used in water electrolysis industry. Great amount of works have been done to develop low-cost alternatives2-4 for the oxygen evolution reaction catalyst like IrO2 and RuO2 which are considered as state of the art OER catalysts, but most of the non-precious metal catalysts still have lower performance than the traditional catalysts. In recent years, a new type of electrocatalyst made of layered double hydroxide5-6 has been reported to outperform the Ir benchmark of OER, drawing my attention on the topic of LDH-based electrocatalyst for water electrolysis. In this project, principal of water electrolysis and properties of layered double hydroxide have been studied with deep insight. Fe, Co, Ni based LDH electrodes have been developed and tested for their electrochemical properties. Brief investigate on the mechanism has been carried out as well.