Chemistry Weekly Seminar - Kazeem Sulaiman, PhD Candidate

Design and Characterization of Silver-Palladium Bimetallic Clusters for Heterogeneous Catalysis

Designing bimetallic clusters with a relatively cheaper and more abundant metal (i.e. using silver (Ag)) rather than gold (Au)), is desirable for the development of heterogeneous bimetallic catalysts for industrial applications. Thiolate-protected Ag-based bimetallic clusters, which are analogues of well-studied Au-based clusters, have yet to be fully explored as heterogeneous catalysts, possibly due to predisposition of Ag to oxidation. This seminar will focus on rational synthesis and characterization of controlled-architectures of silver and silver-palladium (AgPd) bimetallic clusters catalysts for use as selective oxidation and hydrogenation catalysts. Syntheses involve controlled growth of clusters via solution-based synthetic strategies, followed by deposition of the designed clusters onto carbon supports. Strategies and challenges towards the rational synthesis of heterogeneous supported-bimetallic cluster catalysts based on atom-precise monometallic silver cluster precursors will be detailed and contrasted with more traditional routes to synthesize such materials. Characterization methods used to elucidate structures of the synthesized particles before and after activation include X-ray absorption spectroscopy (XAS), which is a valuable characterization method for the characterization of bimetallic clusters, particularly at small length scales. Pair distribution function (PDF) analyses on the Brockhouse beamline have recently been performed to complement XAS work in our group, and early work shows that Ag systems behave significantly differently than analogous Au systems.