Circular utilization of rare earth elements in green hydrogen technologies

Abstract Rare earth elements (REEs) have become important players in the development of sustainable energy, especially in the area of hydrogen production. Hydrogen has drawn a lot of interest as a versatile and carbon-free fuel due to the urgent need for clean and effective energy sources to tackle climate change. Rare earth-based strategies have shown tremendous promise because of their distinct qualities and catalytic powers. An assortment of seventeen chemically related elements known as REEs, such as cerium, lanthanum, neodymium, and others, have excellent magnetic, electrical, and optical capabilities. They have recently been utilised for their ability to produce hydrogen, helping to progress the development of a sustainable energy landscape. Water or other molecules containing hydrogen can be converted into hydrogen gas with the help of ceria-based catalysts because of their special capacity to retain and release oxygen during chemical processes. The thermochemical water-splitting process is one of the popular ways that rare earths are used to produce hydrogen. High temperatures and catalysts based on cerium are used in this process to break down water molecules into hydrogen and oxygen. Because ceria-based redox processes are reversible, the material may be cycled repeatedly, making it an effective and sustainable method of producing hydrogen. Additionally, rare earth elements can improve the stability and general performance of catalysts, allowing for continuous usage and minimising deterioration. Beyond the thermochemical water-splitting procedure, rare earth elements are used to produce hydrogen in other ways. In photoelectrochemical cells, electrolysis systems, and other cutting-edge technologies that attempt to capture clean hydrogen as an energy carrier, researchers are investigating their possibilities. Researchers may enhance the effectiveness and sustainability of these systems by utilising the special features of REEs, paving the way for a greener future. This article intends to analyse the possibilities of rare earth-based hydrogen generation techniques in order to address the rising need for clean energy around the world. Understanding the properties of rare earth elements and their function in catalysis can provide us with important insights into the creation of effective and ecologically friendly hydrogen generation systems, aiding in the shift to a sustainable energy paradigm.