Catalytic Impedance\nSpectroscopy: Concept and Application\non CO<sub>2</sub> Methanation

Complex modeling of periodic excitation combined with\ntime-resolved\nproduct detection is used to describe the complex response function\nof a catalytic system. We describe this concept of catalytic impedance\nspectroscopy (CIS) and the underlying general experimental approach\nand a concrete setup. The feasibility of CIS is experimentally demonstrated\nalong the catalytic CO<sub>2</sub> methanation reaction. The measurements\nconfirm the theoretically anticipated rate-determining step of HCO*\n→ CH* on Ni catalysts. Limitations and prospects of CIS to\nunravel reaction mechanisms are discussed.