Session: General Catalysis:

CeO₂ is known to be very active towards DMMP adsorption and decomposition. Thus, I decided to study how alio-doping (low valence doping, Y^₃₊, La³⁺ and Gd³⁺) influences its interaction with DMMP. I synthesized 10%, 20% and 30% Y³⁺, La³⁺ and Gd³⁺ doped Mesoporous CeO₂with a nano casting method. I characterized those materials with extensive techniques (XRD, neutron diffraction, XPS, IR, SEM, TEM) to understand how doping influences the crystal structure as well as the surface properties. I applied DRIFTS as well as solid state NMR to understand the surface species of doped mesoporous CeO2 during and after exposure of DMMP. Through our experiment, we learned doping of Y³⁺, La³⁺ and Gd³⁺ have very similar effects on interaction of mesoporous CeO₂and DMMP. As doping increases, the DMMP decomposition activity on the surface of mesoporous CeO₂ decreases. We attribute such decrease of activity to the change of the exposed facets, hydrophilicity and reactive under-coordinated metal sites. DFT modeling is used to verify our assumptions.

Tianyu Li

University of Maryland at College Park

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