关键词: |
Chemisorption, Metallic nanoparticles, Chemical synthesis, Biomass, Metal oxides, Catalysts, Temperature, Desorption, Carbon, Catalysis, Dehydration, Hydration, Hydrogenation, Methanols, Micromeritics autochem ii, Core-shell particles, Zeolites, Dispersion, Temperature programmed desorption, Carbon supports, Hydrogenolysis, Tetrahydropyran-2-methanol, 1 6-hexanediol, Heterogeneous catalysis, Thfdm (tetrahydrofuran dimethanol) |
摘要: |
Major Goals: In our proposal entitled, Chemisorption as a versatile tool to characterize multifunctional materials, we requested and received funding for a chemisorption setup, specifically a Micromeritics Autochem II. We proposed several routine experiments using this instrument which would immediately push our research forward. These are repeated below. 1. Controlled synthesis of metal nanoparticles (and core-shell particles), in particular bimetallic systems like RhRe/C and PtMo/C, important catalysts in biomass chemistry (BETO project). It is currently assumed that the active sites are at the interface of the two metals. This implies that one should synthetically aim at depositing small amounts of the oxophilic metal (e.g., Re and Mo) to the noble metal (e.g., Rh or Pt), rather than to the exposed support surface between the metal nanoparticles. The decrease in probe adsorption can be connected with the deposition of the oxophilic metal on the noble metal, rather than on the support, provided that the particles did not sinter (which needs to be verified with microscopy) and the probe molecule does not bind to the oxophilic metal sites. 2. Zeolites are a class of materials used in a number of our projects, related to biomass, as well as important commodities chemistry like Bayer-Villiger oxidations and epoxidations. Determining their acid/base properties would allow a correlation of these properties with the catalytic activity of different materials. These materials are not always stable with time-on-stream and tend to deactivate. An analysis of the acid/base properties before and after reaction would help in understanding such effects better. Furthermore, it is common to postsynthetically modify zeolites, e.g. by steaming, a process that is still poorly understood. Also here, the effects of different parameters during the steaming on the acid/base properties could be studied. |