The improved hydrogen generation kinetics from hydrolysis of chemical hydrides using an electroless-deposited Co-(Ni/Fe)-P catalysts

Abstract

The hydrogen is light and abundant. It can also be used as a fuel of polymer electrolyte membrane fuel cell (PEMFC), which is the promising next-generation energy conversion system. Presently, the hydrogen is mostly produced by a steam reforming process in the industry, but the final product contains carbon oxides, which cause the environmental pollutant and accelerate degradation of the PEMFC. The hydrogen storage is also very difficult technique due to its flammability and low melting point. To solve these problems, the technique using the chemical hydrides with high energy storage density and safety has been developed. Specifically, the chemical hydrides such as sodium borohydride (NaBH4) can react with the water at room temperature and produces pure hydrogen which is called hydrolysis, and it can be stored stably in alkaline media. The key issue of this study is to increase the hydrogen generation kinetics from the hydrolysis using the engineered catalysts. Previously, the noble metal (Pt, Ru, etc.) based catalysts have been used. The noble metal-based catalysts showed the good performances, but these are so expensive and hence are difficult to be used practically. In this presentation, we will introduce the new transition metal based catalyst of Co-(Ni-Fe)-P fabricated by an electroless-deposition, which is optimized by controlling pH and bath temperature. The optimized Co-Ni-Fe-P catalyst generates the hydrogen at the rate of 4300 ml g-1 min-1 at 60oC, which is enough value to be used for on-board hydrogen production system. To observe the micro-structures and chemical compositions, and surface morphology, XRD, HR-TEM, XPS, and SEM/EDS were used.