GB (sarin), a chemical ware fare agent (CWA), due to its extreme fatal toxicity and its involvement in a few terrorist and battle attacks, has become an increasing concern for the national public and military safety. Developing filter materials that can strongly adsorb and effectively decompose GB thus attracts growing research interest. The great diversity of metaloxides and their abundant surface chemistry suggest an opportunity to realize their potential as filter materials. This dissertation outlines our effort to gain a fundamental understanding of the interaction between GB (also its simulant DMMP) and metal oxides. We aim to determine the structural factors that influence the performance of metal oxides on adsorbing and decomposing GB and to ultimately predict the behavior of a given metal oxide. We used two mesoporous metal oxides (TiO2 and CeO2) as two model systems and performed systematic studies on their interaction with GB and its simulant DMMP. We utilized multiple techniques to fully characterize the crystal and surface characters of the mesoporous metal oxides. The interactions between GB/DMMP and metal oxides were explored by different spectroscopic techniques (majorly infrared techniques). Combining the experimental observations and DFT calculations on two different metal oxides, we propose several governing parameters of the metal oxides to impact their reactivity for decomposing GB. We also derive a simplified and qualitative model to predict the reaction behavior and activity of metal oxides when interacting with GB.