Rare earth elements (REEs) are essential for modern technology, from smartphones to renewable energy equipment. Yet separating these metals from one another is a major challenge.
A team of researchers at Penn State, led by chemistry professor Joseph Cotruvo, Jr., has discovered a groundbreaking solution using a naturally occurring protein.
This protein, called LanD, can efficiently separate valuable rare earth elements like neodymium and praseodymium, which are crucial for high-tech and green energy applications.
Each REE has unique properties that make it useful for different purposes.
For example, neodymium is critical for making permanent magnets used in smartphones and wind turbines.
However, REEs are notoriously difficult to separate due to their similar chemical properties.
Current methods for separating them are expensive, inefficient, and heavily rely on toxic chemicals, making the process both costly and environmentally harmful.
Cotruvo’s team has developed a protein-based solution that could offer a cleaner, cheaper way to separate these metals. LanD, a protein from the bacterium Methylobacterium extorquens, naturally binds to certain REEs.
This bacteria, which grows on simple compounds like methanol, requires specific REEs like lanthanum and cerium for growth. However, it also encounters other rare earth elements that are less useful for its survival.
Here’s where LanD and another protein, LanM, come into play. While LanM binds to REEs generally, LanD specializes in binding the more valuable light REEs, especially neodymium and praseodymium.
The LanD protein has a unique binding site that acts like a specialized “lock” for these valuable REEs, effectively separating them from others. “LanD has a natural preference for neodymium,” Cotruvo explained.
This discovery has the potential to revolutionize rare earth separation, making it more environmentally friendly and reducing reliance on imported REEs, as nearly 80% of the U.S. supply currently comes from overseas.
The research team has improved LanD’s ability to separate these elements by re-engineering the binding site. This modification allows LanD to target neodymium and praseodymium even more effectively, “locking out” less valuable metals.
The protein’s unique structure is so effective that it competes with current industry methods, offering similar or even better separation capabilities without the need for harmful chemicals. This advance could make it easier to extract these valuable metals from mixed sources like recycled tech or mining waste.
Using proteins like LanD and LanM together could create an efficient, eco-friendly process for separating complex REE mixtures. With LanM excelling at separating heavier REEs and LanD focusing on valuable light REEs, the two proteins can work in tandem to sort different elements more precisely.
This teamwork not only benefits REE separation but also helps keep undesirable elements from interfering with each other inside the bacterium.
The Penn State team envisions future developments to make the LanD protein even more efficient and adaptable for large-scale use. Cotruvo hopes this discovery will inspire new protein-based methods for sorting other difficult-to-separate metals, paving the way for greener mining practices.
The researchers’ work, published in the Proceedings of the National Academy of Sciences, holds promise for reshaping how we obtain and use rare earth elements. By harnessing nature’s own tools and enhancing them in the lab, scientists may have found a sustainable path forward for REE mining.
Source: Penn State.
