In order to improve the thermal stability of silicone rubber (SR), cerium-tin composite oxides (CeSnO-x) are used as thermo-oxidative stabilizer in phenyl methyl vinyl silicone rubber (PVMQ). CeSnO-x are synthesized via the sol–gel method and characterized by scanning electron microscopy, x-ray diffraction, and X-ray photoelectron spectroscopy (XPS) showing that tin doping led to more oxygen vacancies in CeSnO-x compared to CeO 2 . Through thermogravimetric analyzer, differential scanning alorimetry (DSC) and average activation energy calculation of PVMQ with different thermo-oxidative stabilizer, it was found that CeSnO-8 is outperforming CeO 2 , SnO 2 , and their mixtures in improving the thermo-oxidative stability of PVMQ. In mechanical property tests, due to tin doping, CeSnO-8 exhibit superior performance at all stages during thermo-oxidative aging comparing the different effects of CeO 2 and SnO 2 in different aging stages. XPS of PVMQ composites investigate the mechanism by which CeSnO-8 exhibit different effects. Fourier transform infrared spectroscopy characterizing the Si-C and Si-O bond changes in PVMQ composite before and after aging and the measurement of Mc explore thermo-oxidative stabilizers' role during thermo-oxidative aging of PVMQ. Thermogravimetry-infrared spectroscopy comparisons between unstabilized PVMQ and CeSnO-8-stabilized PVMQ show that CeSnO-8 effectively quenched radicals produced by the oxidation of the PVMQ side group, but exacerbate degradation caused by molecular chain rearrangement.
Meng Wang,Yan Zhang,Wenpo Shan,Yunbo Yu,Jingjing Liu,Hong He
The thermal stability of the catalysts is of particular importance but still a big challenge for working under harsh conditions at high temperature. In this study, we report a strategy to improve the thermal stability of the ceria-based catalyst via introducing Sn. XRD, Rietveld refinement, and other characterizations results indicated that the formation of Sn-Co solid solution plays a key role in the thermal stability of the catalyst. The developed ternary 3%Co/Ce 0.5 Sn 0.5 O 2 catalyst not only exhibits outstanding thermal stability and resistance to SO 2 and H 2 O for soot oxidation from diesel vehicle exhaust but also remains extraordinary thermal stability for CO oxidation. Remarkably, even after thermal aging at 1000°C, it still possessed high catalytic activity similar to that of the fresh catalyst.
The development of detection devices with rapid response, high sensitivity, and precise detection capabilities for heavy metal ions remains a research hotspot in environmental protection and food safety. In this study, a facile and efficient synchronous doping/etching strategy was employed to synthesize hierarchically porous bimetallic MOF-derived CeSn@C-10 material. Comprehensive characterization techniques, including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) revealed that the incorporation of Sn species significantly enhanced oxygen vacancy concentration in the CeO 2 lattice while stabilizing low-valent Ce 3+ species, thereby boosting the electrocatalytic activity for CeSn@C-10. The hierarchical porous architecture endowed the material with an enlarged specific surface area and improved accessibility to active sites. When fabricated into an electrochemical sensor (CeSn@C-10/GCE), it exhibited exceptional Cu 2+ detection performance with dual linear ranges of 0.2–5 μM and 5–60 μM, achieving a low detection limit of 38 nM (S/N = 3). The sensor demonstrated remarkable anti-interference capability and promising applicability in real-sample analysis. This work provides a novel strategy for designing hierarchically porous bimetallic electrochemical sensors through synergistic enhancement mechanisms.
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