Paramorphism effect could be an effective strategy to design efficient catalysts, but have been rarely explored. In this study, to achieve efficient catalysts for elimination of NO and CO together, Ce₂Sn₂O₇ pyrochlore and Ce₂Sn₂O_8+x solid solution paramorphs were purposely synthesized to support FeO_x. It is found that Fe/Ce₂Sn₂O₇ displays better reaction performance than Fe/Ce₂Sn₂O_8+x. H₂-TPR results have demonstrated that the dispersed FeO_x has differed interaction with the two types of supports. EPR and DFT calculation have testified that it is easier to generate surface vacancies on Fe/Ce₂Sn₂O₇ than on Fe/Ce₂Sn₂O_8+x, thus forming more abundant active oxygen sites. Furthermore, the total number of Lewis and Brønsted sites on Fe/Ce₂Sn₂O₇ is larger. In addition, reactive NH₄⁺ linked to Brønsted acidic sites and bridge nitrite are uniquely formed on Fe/Ce₂Sn₂O₇, thus leading to its much better performance than on Fe/Ce₂Sn₂O_8+x. Notably, Fe/Ce₂Sn₂O₇ exhibits also better sulfur and water tolerance. On both catalysts, the NH₃-SCR reaction obeys a Langmuir-Hinshelwood pathway, while the CO oxidation follows a Mars-van Krevelen mechanism. In summary, a paramorphism effect is obvious observed, which could give people some new thoughts to design high-performance catalysts.

Friction dampers dissipate seismic energy through sliding but lack self-sensing capability. This study integrates friction dampers with triboelectric nanogenerators (TENGs), which convert mechanical energy into electrical signals, creating a self-sensing damper. Using friction pairs with large triboelectric differences, the system simultaneously achieves energy dissipation and sensing. During sliding, mechanical energy is partially converted into heat (dissipation) and electricity (sensing). Theoretical models link displacement and velocity to voltage and current, validated through cyclic loading tests varying velocity, displacement, and friction force. Results show stable energy dissipation (300-770 J/cycle) comparable to conventional dampers. Sensing performance is strong: voltage correlates linearly with displacement (0.00526 V/mm, R² = 0.94), and current with velocity (0.01914 μA/(mm/s), R² > 0.99). Unlike conventional TENGs, high friction alters triboelectric behavior via wear and heating, producing a unique voltage-velocity relationship. Scanning electron microscopy analysis confirms maximum wear at 34.2 kN, aligning with inflection points in electrical response. An empirical Q-V-f formula for high-friction conditions enriches triboelectric theory and guides damper design, emphasizing friction optimization for balanced dissipation and sensing stability.