129Xe NMR analysis of pore structures and adsorption phenomena in rare-earth element phosphates

Rare-earth elements (REEs) are indispensable in various applications ranging from catalysis to batteries and they commonly found phosphate minerals. Xenon is an excellent exogenous NMR probe for materials because it inert its 129 Xe chemical shift very sensitive local physical or environment. Here, we exploit, the first time, characterization of porous structures adsorption properties REE phosphates (REEPO 4 ). We study four different REEPO samples (REE = La, Lu, Sm Yb), including both light (La Sm) heavy (Lu Yb) as well diamagnetic Lu) paramagnetic (Sm REEs. resonances moisture content samples. In treated at a lower temperature (80 °C), free water hinders access hydrophobic xenon into small mesopores, but treatment higher (200 °C) removes allows explore mesopores. Based on standard two-site exchange model analysis variable-temperature shifts, proposed, novel modification materials, average mesopore sizes were determined. The size was largest (79 nm) La sample with mixed monazite (70%) rhabdophane (30%) phases smallest (6 Yb pure xenotime phase. Lu (12 6 differed by factor two regardless their similar revealed that heats similar, varying between 8.7 10.1 kJ/mol. For samples, computational modelling confirmed order magnitude shifts adsorbed surfaces therefore validity analysis. Overall, provides exceptionally versatile information about pore which may be useful developing extraction processes • Rare Earth Elements critical many high technology applications. Phosphate compounds one prevalent hosts 3+ ions time used Analysis reveals sizes, effect moisture. Computational confirms