Underpotential Deposition 欠电位沉积 报告人：王文心

Contents 1 Underpotential Deposition 2 The Mechanism of UPD 3 UPD on Different Metals 4 Application of UPD

Underpotential Deposition Underpotential deposition (UPD) is a phenomenon of electrodeposition of a species (typically reduction of a metal cation to a solid metal) at a potential less negative than the equilibrium (Nernst) potential for the reduction of this metal. Beginning Analysis Mechanism Application 1910s 1940s 1970s now

The Mechanism of UPD  

The Thermodynamic Mechanism of UPD        

The Thermodynamic Mechanism of UPD            

Under Potential Displacement         D. M. Kolb, M. Przasnyski, H. Gerischer, Underpotential deposition of metals and work function differences, Journal of Electroanalytical Chemistry, 1974, 54:25

The Common Characteristics The work function and the side-action varies with the coverage changes UPD potential affect the adsorption valences UPD changes potential distribution and solvent molecules microscopic arrangement on interface Common Characteristics The first monolayer effects further deposition. More than one UPD peak; lattice structure is different with different deposition potential; coverage increase when potential near the bulk peak

UPD on Different Metals substrate material solution Different Metals Contents Reactants Electrolyte pH Value Additive Singlecrystal Surface Polycrystal Surface Ag+/Pt Ag+/Pd Ag+/Au Cd2+/Pt Cd2+/Au Cd2+/Cu Cd2+/Ag ΔEUPD / V 0.44 0.30 0.51 0.96 0.23 0.16 Solution H2SO4 HClO4 Na2SO4 C / mol/L 0.5 1.0 D. M. Kolb，Advances in Electrochemistry and Electrochemical Engineer. New York: John Wiliy,1978, 11:125

Different Systems Electrode UPD ions Pt Ag+、Cu2+、Hg2+、Pb2+、Bi3+、Cd3+、Tl+、Sb3+、Ge4+、Sn4+ Au Ag+、Cu2+、Hg2+、Pb2+、Bi3+、Cd3+、Tl+、Sb3+、Sn4+、Zn2+、Pd2+ Ag Cu2+、Pb2+、Bi3+、Cd3+、Tl+、Sn4+、Zn2+ Pd Ag+、Cu2+、Bi3+、Cd3+、Pb2+、Tl+、Sn4+ Cu Cd3+、Pb2+、Tl+ Glassy Carbon Ag+、Cu2+、Hg2+、Pb2+、Bi3+

Different Research Method 1. potential sweep method 1 5 4. XPS 2 4 5. Electrochemical spectroscopy 2. potential step method 3 3. RRDE method

Yangchuan Xing, et al. J. Phys. Chem. Lett. 2010, 1, 3238–3242 The Application of UPD Cu UPD-galvanic replacement has become a useful method to prepare catalyst. Models of pseudomorphic monolayers of Pt on three different substrates inducing compressive strain (Ru(0001) and Pd (111)) and tensile strain (Au(111)) R R Adzic, et al，Platinum monolayer fuel cell electrocatalysts. Topics in Catalysis, 2007, 46 (3–4): 249–262 Yangchuan Xing, et al. J. Phys. Chem. Lett. 2010, 1, 3238–3242

The Application of UPD Facile Fabrication of Ultrathin Pt Overlayers onto Nanoporous Metal Membranes via Repeated Cu UPD and in Situ Redox Replacement Reaction

The Application of UPD Cu Cu UPD Pt UPD Au replacement Cu UPD –Au replacement R. Wang, et al., Adv. Mater. 2010, 22, 1845.

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