Crystal engineering of platinum to enhance the efficiency of hydrogen isotopes enrichment via water vapor adsorption

Abstract

Catalytic exchange technology is state-of-the-art to enrich hydrogen isotopes in nuclear wastewater through platinum (Pt)-based catalyst. Most researchers focus on developing hydrophobic supports to inhibit direct coverage of Pt by liquid water, while the structure-activity relationship between active sites and water vapor is ignored. Herein, we prepare a series of Pt-based model catalysts (Pt/MON-t) by crystal engineering of Pt to determine the effect of water vapor. Combining the results of X-ray diffraction characterization, density functional theory calculation, and catalyst evaluation, the quantitative results of water vapor adsorption behavior are found to show a linear correlation with catalytic efficiency (R2 = 0.94), proving the water vapor adsorption behavior is mainly responsible for the difference in efficiency, and the weaker water vapor adsorption is more favorable to achieve higher catalytic efficiency. As the weakest adsorption energy of water molecule, Pt/MON-120 exhibits the highest catalytic efficiency with 91.4% at 353.15 K, and maintains excellent stability.