Scientists at UT Austin unveil a new method for extracting rare earth elements more efficiently and sustainably. This advancement could significantly impact technology and energy sectors by reducing reliance on imports.
A new approach to extracting rare earth elements, essential for powering devices from electric vehicle batteries to smartphones, could increase domestic supplies and reduce dependency on costly imports. This breakthrough comes from researchers at The University of Texas at Austin, who have developed a new, environmentally friendly method for separating and extracting these critical materials.
Rare earth elements are vital to numerous advanced technologies, but their traditional extraction and purification processes are both energy-intensive and costly.
“Rare earth elements are the backbone of advanced technologies, but their extraction and purification are energy intensive and extremely difficult to implement at the scales required,” Manish Kumar, a professor in the Cockrell School of Engineering’s Fariborz Maseeh Department of Civil, Architectural and Environmental Engineering and the McKetta Department of Chemical Engineering, said in a news release. “Our work aims to change that, inspired by the natural world.”
The research, recently published in the journal ACS Nano, describes the creation of artificial membrane channels. These tiny pores, inspired by biological systems’ selective transport mechanisms, can efficiently differentiate between ions.
Each channel is uniquely designed to permit only ions with specific characteristics while excluding others, a process essential to numerous biological functions, including cognitive processes.
These man-made channels employ a modified pillararene structure to significantly enhance their ability to selectively bind and transport middle rare earth elements like europium (Eu³⁺) and terbium (Tb³⁺) while excluding more common ions such as potassium, sodium and calcium.
“Nature has perfected the art of selective transport through biological membranes,” added Venkat Ganesan, a professor in the McKetta Department of Chemical Engineering, who co-led the research. “These artificial channels are like tiny gatekeepers, allowing only the desired ions to pass through.”
Middle rare earth elements have distinct properties making them indispensable for specific applications, such as lighting, displays and green energy technologies, including wind turbines and electric vehicle batteries.
The U.S. Department of Energy and the European Commission have flagged these elements, including europium and terbium, as critical materials at risk of supply disruption. As demand for these elements is expected to surge by over 2,600% by 2035, sustainable extraction and recycling methods are urgently needed.
Experimental results from these artificial channels revealed a preferential selection of europium over other rare earth elements, exhibiting a 40-fold preference over lanthanum and a 30-fold preference over ytterbium.
These selectivity levels far surpass those achieved by traditional solvent-based methods, significantly reducing the number of stages necessary for separation.
Advanced computer simulations helped uncover that the channels’ selectivity is driven by the unique interactions between water molecules and the rare earth ions within the channels.
These interactions enable the channels to distinguish between ions based on their hydration dynamics — how water molecules surround and interact with them.
Kumar and his team, who have been pursuing this research for over five years, also foresee broad industrial applications. They anticipate integrating their technology into scalable membrane systems powered by clean energy.
Their ongoing work includes developing a platform that can select and gather a variety of ions, potentially encompassing other critical minerals like lithium, cobalt, gallium and nickel.
“This is a first step towards translating nature’s sophisticated molecular recognition and transport strategies into robust industrial processes, thus bringing high selectivity to settings where current methods fall short,” added Harekrushna Behera, a research associate in Kumar’s lab.