ZSM-5 zeolite is usually used in gas sensors as an auxiliary material to improve the gas-sensitive properties of other semiconductor materials, such as its molecular sieve properties and surface adsorption properties. Here, the gas-sensitive mechanism analysis of SnO/zeolite gas sensors is studied for the first time based on the perspective of zeolite as a band gap-tunable semiconductor that was reported recently. The gas-sensing mechanism of the zeolite/semiconductor has been modeled based on the surface charge theory, and the work function of the ZSM-5 zeolite has been revealed for the first time. A heterostructure of Ag and ZSM-5 was designed and compounded to tune the band gap of the ZSM-5 zeolite by the ammonia pool effect method. The band gap width of the zeolite decreases from 4.51 to 3.61 eV. A series of characterization techniques were used to analyze the distribution and morphology of silver nanoparticles in zeolites and the variation of the ZSM-5 band gap. Then, SnO/Ag@ZSM-5 sensors were fabricated, and the gas-sensing performances were measured. The gas-sensing results show that the SnO/Ag@ZSM-5 sensor has an improved response to formaldehyde in particular compared to the SnO sensor. The response value of the SnO/Ag@ZSM-5 sensor to 70 ppm formaldehyde reached 29.4, which is a 528% improvement compared to the SnO sensor. Additionally, the selectivity was greatly enhanced. This study provides a strategy for designing and developing higher-performance gas sensors.
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http://dx.doi.org/10.1021/acsami.3c12789 | DOI Listing |
J Colloid Interface Sci
January 2025
Faculty of Chemical Engineering, Kunming University of Science and Technology, Kunming 650500, PR China; Yunnan Provincial Key Laboratory of Energy Saving in Phosphorus Chemical Engineering and New Phosphorus Materials, Kunming 650500, PR China. Electronic address:
Phosphorus (P)-doping H-ZSM-5 zeolites, which is crucial for industrial applications, aim to adjust both acidity and framework stability while optimizing product distribution in heterogeneous catalysis. Nonetheless, current phosphating methods often suffer from inadequate phosphorus dispersion and unclear interfacial interactions with framework aluminum (Al). In this work, P-doping ZSM-5 zeolites were successfully one-step prepared by using tributylphosphine served as an organophosphorus precursor, assisting by density functional theory calculations.
View Article and Find Full Text PDFScience
January 2025
Wolfson Catalysis Centre, Department of Chemistry, University of Oxford, Oxford, UK.
The distribution of substitutional aluminum (Al) atoms in zeolites affects molecular adsorbate geometry, catalytic activity, and shape and size selectivity. Accurately determining Al positions has been challenging. We used synchrotron resonant soft x-ray diffraction (RSXRD) at multiple energies near the Al K-edge combined with molecular adsorption techniques to precisely locate "single Al" and "Al pairs" in a commercial H-ZSM-5 zeolite.
View Article and Find Full Text PDFJ Phys Chem C Nanomater Interfaces
January 2025
Center for Materials Science and Nanotechnology (SMN), Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, Oslo N-0315, Norway.
The flexibility of the H-ZSM-5 zeolite upon adsorption of selected coke precursors was investigated using both theoretical and experimental approaches. Four structural models with varying active site locations were analyzed through density functional theory (DFT) simulations to determine their responses to different types and quantities of aromatic molecules. Complementary experimental analysis was performed, allowing for a direct comparison with the theoretical findings, using thermogravimetric analysis (TGA), nitrogen adsorption (N adsorption), solid-state NMR, and X-ray diffraction (XRD).
View Article and Find Full Text PDFInorg Chem
January 2025
State Key Laboratory of Molecular & Process Engineering, SINOPEC Research Institute of Petroleum Processing, Beijing 100083, China.
The ZSM-5 zeolite is the key active component in high-severity fluid catalytic cracking (FCC) catalysts and is routinely activated by phosphorus compounds in industrial production. To date, however, the detailed structure and function of the introduced phosphorus still remain ambiguous, which hampers the rational design of highly efficient catalysts. In this work, using advanced solid-state NMR techniques, we have quantitatively identified a total of seven types of P-containing complexes in P-modified ZSM-5 zeolite and clearly revealed their structure, location, and catalytic role.
View Article and Find Full Text PDFEnviron Sci Technol
January 2025
Tianjin Key Lab of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, P. R. China.
Designing catalysts with both activity and stability remains a grand challenge for the removal of chlorinated volatile organic compounds (CVOCs) by catalytic oxidation. Herein, the Ru-Mn subnanometric species encapsulated in ZSM-5 zeolite (RuMn@Z) was synthesized. It shows that the 90% conversion of dichloromethane is as low as 320 °C, which is significantly lower than that of Ru@Z (350 °C) and the impregnation catalyst (RuMn/Z, 355 °C).
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