Cryogenic TDS Platform for Quantitative Hydrogen Isotope (H2/D2/HD) Separation via Quantum Sieving in Porous Materials

Abstract

Accurate evaluation of hydrogen isotope separation performance is critical for the development of advanced porous materials for energy, semiconductor, and nuclear applications. Herein, we report the development of an advanced cryogenic thermal desorption spectroscopy (AC-TDS) platform capable of quantitatively analyzing hydrogen isotopes (H2, D2, and even HD) over a wide temperature range (15 ? 900 K). The system incorporates calibration standards such as TiH2 and Pd95Ce5 alloy, enabling reliable quantification of desorbed gases. By varying the gas exposure temperature, time, and pressure, we can elucidate the microscopic nature of adsorption processes associated with structural flexibility, pore accessibility, or strong adsorption sites. With binary (H2/D2) and ternary (H2/HD/D2) isotope gas mixtures, AC-TDS directly determines isotope-dependent uptakes and selectivities using small quantities of samples and extracts desorption energetics via multi-rate analysis. Using specific gas exposure conditions, the TDS technique offers a powerful diagnostic tool for understanding adsorption energetics, framework dynamics, and isotope selectivity, and allows a rapid characterization of porous materials for hydrogen isotope separation applications based on selective adsorption.