염기성 전해질에서의 비귀금속 나노구조 수소생성반응 촉매 개발

Abstract

As interest in hydrogen fuel as an alternative to fossil fuels increases, the importance of environmentally friendly hydrogen production methods is constantly being emphasized. Hydrogen production through electrochemical water decomposition is a representative example and is evaluated as the eco-friendliest production method because renewable energy can be used. A key issue in this water electrolysis is the development of hydrogen evolution reaction (HER) catalysts that can dramatically lower overpotentials. In the case of catalysts developed so far, noble metal catalysts show high efficiency, but low economic feasibility due to high prices and low stability during reactions are a problem. In addition, alkaline HER has attracted attention due to the corrosion problems of water electrolysis components and expensive OER catalysts in acidic media. However, alkaline HER suffers from the problem of energy barrier, which results from the higher activation energy of the additional water dissociation step (H2O + e- → OH- + H*). To solve these problems, transition metal catalysts based on tungsten (W) have been developed owing to its superior HER activity resulted from high conductivity and modulated electronic structure with defect engineering. However, they still show lower performance than noble metal catalysts. In this study, in order to overcome the limitations of such W-based catalysts in alkaline HER, catalyst nanostructuring and synthesis were carried out considering the adsorption energy between water and catalyst.