Student Inorganic Chemistry Seminar with Deiaa Harraz (MIT- Surendranath Group)

, 4-730

Electrochemistry uncovers the interplay of heterogeneous and homogeneous catalysis in vinyl acetate synthesisAbstract: The fields of heterogeneous catalysis and homogeneous catalysis have traditionally been viewed as disparate areas of study. However a number of prominent examples have shown that heterogeneous materials can produce homogeneous active species under catalytic conditions, and vice versa. In this talk we examine the dynamic interplay between heterogeneous and homogeneous catalysis in the case study of palladium catalyzed vinyl acetate synthesis. This reaction has been viewed as a nominally gas-solid heterogeneous catalytic process, however some investigators have suggested a possible role of homogeneous Pd(II) that could form in thin wetting layers at the catalyst surface. Borrowing tools from electrochemistry and corrosion science, we uncover the critical role of the dynamic formation of homogeneous Pd(II) during this reaction. We find that both heterogeneous Pd metal and homogeneous Pd(II) carry out complementary steps to furnish the catalytic cycle, and that the interconversion between Pd metal and Pd(II) is essential to the function and determines the rate of catalysis. These findings highlight a rich opportunity to couple heterogeneous and homogeneous elements in the design of catalytic transformations.Refreshments will be served outside of 4-370 at 4:00PM