Well-defined metal-oxide catalysts to understand fundamental chemical transformations of biomass-derived molecules
EMSL Project ID
49339
Abstract
Detailed, accurate and unambiguous structure/function relationships in metal-oxide catalyzed reactions are essential in the design of efficient catalysts for the conversion of biomass-derived feedstocks to value-added functional chemicals and useful fuels. To achieve this goal, we propose to address a number of important fundamental issues related to the surface chemistry, reactivity and stability of metal oxide catalysts useful for individual reactions in biomass conversion in the presence of condensed water, or catalytic conversion of biomass-derived small molecules in the presence of water vapor. Specifically, we will use a range of model catalysts, containing either supported or unsupported metal oxides with varying acid/base and redox chemical properties. We will also study POM-based clusters which exhibit well-defined cluster size and atomic connectivity, diverse chemical compositions obtained by varying central, addenda, and exchange atoms. These properties make them ideally suited to elucidate the effects of chemical composition, atomic connectivity, and cluster size on acid and redox properties, as well as the consequences of these properties for catalysis by metal oxides. To probe the catalytic chemistry useful for understanding biomass conversion reactions, we will use a set of relatively simple acid and redox reactions that are representative of the relevant transformations (e.g. deoxygenation, hydrogenolysis and hydroalkylation). Our studies seek to elucidate the functional and structural requirements for C-O and C-H bond activation, oxygen insertion, and (typically) undesirable deep oxidation reactions. In acid chemistry, alcohol dehydration reactions represent relatively simple probes of Brønsted acid chemistry, accessible to detailed mechanistic studies and theoretical calculations. Linear, branched, cyclic and aromatic molecules with varying functional groups can be used to identify a full range of reactivity issues. Here, we probe the structural and chemical requirements for such critical elementary steps as hydrogen transfer and skeletal rearrangements (e.g., isomerization). This work will allow us to develop rules for chemical reactivity for more complex molecules including, for example, those with increasingly substituted carbon centers. Finally, the influence of co-adsorbed and condensed water on the structure of catalytic oxides, and on the elementary steps, intermediates, and transition states that mediate their redox and acid/base chemistry will be probed on realistic and well-defined catalyst materials. In these studies, we will first examine the impact of water on the transport of reactants and products to and from the catalytic surfaces. We will also identify the localized impact of water on the active sites and the absolute and relative stabilization of the reactive transition states due to the presence of small numbers of water molecules near the active site as well as the presence of bulk water. Eventually, we will investigate how water modifies catalytic surfaces via such mechanisms as surface relaxation, recrystallization, and/or partial dissolution/precipitation reactions.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2016-10-01
End Date
2018-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Co-Investigator(s)
Team Members
Related Publications
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Hensley A, Y Wang, D Mei, and JS McEwen. 2018. "Mechanistic Effects of Water on the Fe-Catalyzed Hydrodeoxygenation of Phenol. The Role of Brønsted Acid Sites." ACS Catalysis 8(3):2200-2208. doi:10.1021/acscatal.7b02576
Jaegers NR, C Wan, MY Hu, M Vasiliu, DA Dixon, ED Walter, I Wachs, Y Wang, and JZ Hu. 2017. "Investigation of silica-supported vanadium oxide catalysts by high-field 51V Magic Angle Spinning NMR." The Journal of Physical Chemistry C 121(11):6246–6254. doi:10.1021/acs.jpcc.7b01658
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Shi Q., C. Zhu, S. Feng, D. Du, J. Wang, H. Xia, and M.H. Engelhard, et al. 2018. "Ultrathin Dendritic IrTe Nanotubes for Efficient Oxygen Evolution Reaction with a Wide pH Range." Journal of Materials Chemistry A 6, no. 19:8855-8859. PNNL-SA-130853. doi:10.1039/c8ta01288a
Wang A, B Lin, H Zhang, MH Engelhard, Y Guo, G Lu, CHF Peden, and F Gao. 2017. "Ambient Temperature NO Oxidation Over Cr-based Amorphous Mixed Oxide Catalysts: Effects From the Second Oxide Components." Catalysis Science & Technology 7(11):2362-2370. doi:10.1039/c7cy00490g
Wang M., N.R. Jaegers, C. Wan, J.Z. Hu, H. Shi, D. Mei, and S.D. Burton, et al. 2019. "Genesis and Stability of Hydronium Ions in Zeolite Channels." Journal of the American Chemical Society 141, no. 8:3444-3455. PNNL-SA-136963. doi:10.1021/jacs.8b07969