Sulfur-doped carbon/TiO2 composites for ethylene photo-oxidation. Enhanced performance by doping TiO2 phases with sulfur by mobile species inserted on the carbon support
Lorena T. Pérez-Poyatos, Sergio Morales-Torres, Luisa M. Pastrana-Martínez, Francisco J. Maldonado-Hódar
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引用次数: 0
Abstract
The performance of carbon xerogel/TiO2 composites in ethylene photo-oxidation was analyzed under dynamic conditions considering various parameters, namely sulfur doping, dry vs. humid conditions and type of radiation (ultraviolet, UV, vs. visible light, Vis). The catalysts were synthesized using an acid-catalyzed sol-gel process and characterized with complementary techniques, including SEM/EDX, XRD, XPS and physical adsorption of N2 and CO2, among others. The performance of samples in ethylene removal by adsorption and photo-oxidation under dynamic flow was discussed and related with their physicochemical properties and the experimental conditions. Although ethylene adsorption was hindered by doping and humidity, both factors were found to enhance photoactivity by promoting the formation of highly oxidant hydroxyl radicals (HO•). The composites showed an improved catalytic performance compared to bare TiO2, with sulfur improving the activity by approximately 8 %. The presence of the carbon material also enhanced the performance under Vis radiation by nearly 25 %. It was suggested that sulfur species could migrate from the carbon support to the TiO2 nanoparticles during carbonization, forming Ti-O-S bonds. This finding constitutes a novel, cost-effective, sustainable and scalable method for the preparation of supported and doped TiO2 nanocomposites.
期刊介绍:
Catalysis Today focuses on the rapid publication of original invited papers devoted to currently important topics in catalysis and related subjects. The journal only publishes special issues (Proposing a Catalysis Today Special Issue), each of which is supervised by Guest Editors who recruit individual papers and oversee the peer review process. Catalysis Today offers researchers in the field of catalysis in-depth overviews of topical issues.
Both fundamental and applied aspects of catalysis are covered. Subjects such as catalysis of immobilized organometallic and biocatalytic systems are welcome. Subjects related to catalysis such as experimental techniques, adsorption, process technology, synthesis, in situ characterization, computational, theoretical modeling, imaging and others are included if there is a clear relationship to catalysis.