Historical Overview and Fundamental Aspects of Molecular Catalysts for Energy Conversion

Tuning the Performance of Low-Pt Polymer Electrolyte Membrane Fuel Cell Electrodes Derived from Fe2O3@Pt/C Core–Shell Catalyst Prepared by an in Situ Anchoring Strategy

“…The literature , shows that addition of a second metal exhibits an increase of surface d-vacancy, which facilitates electron donation from oxygen to the surface Pt. This brings strong interaction between Pt and oxygen, which results in enhancement of oxygen adsorption and weakening of the O–O bond, leading to fast scission of the bond and enhanced ORR activities. ,,, …”

“…The enhanced activity of Fe 2 O 3 @Pt/C can be ascribed to the multiple features such as high ECSA, electronic modifications, and synergistic effects enjoyed by the system all the while avoiding the chance for the ohmic component of the core material to dominate and consequently upset the expected improvement in performance. The literature , shows that addition of a second metal exhibits an increase of surface d-vacancy, which facilitates electron donation from oxygen to the surface Pt. This brings strong interaction between Pt and oxygen, which results in enhancement of oxygen adsorption and weakening of the O–O bond, leading to fast scission of the bond and enhanced ORR activities. ,,, …”

Mechanism of Water Oxidation Catalyzed by a Dinuclear Ruthenium Complex Bridged by Anthraquinone

“…Water oxidation is the so-called "bottleneck of artificial photosynthesis" because of the simultaneous transfer of four electrons and the relatively high equilibrium electrode potential (1.23 V vs. NHE at pH 0) [11]. Many complexes containing Ru, Mn, Ir, Fe, Cu, and Co have been reported as molecular water oxidation catalysts [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]. One advantage of using molecular catalysts is the possibility of elucidating the reaction mechanism.…”

Spectroelectrochemical evidence of the role of viologen moiety as an electron transfer mediator from ITO substrate to a Pt complex acting as a confined molecular catalyst for hydrogen evolution reaction

“…Because of high cost and limited resources, many efforts have been made to develop non-precious metal catalyst and maximize the utilization of these elements. Although molecular and single atom catalysts are expected to have 100% atom efficiency [4][5][6][7][8], both have difficulties in practical use. Molecular catalysts are usually used as homogeneous catalyst in solution and are difficult to be separated from reactants and products after the reaction.…”

“…If electron is transferred via viologen moiety, there is a possibility that viologen radical cation (V +• ), which is formed by one electron reduction of viologen di-cation (V 2+ ) and has a unique absorption in UV/vis spectra around 600 nm [13][14][15], can be detected spectroelectrochemically as an intermediate state upon potential step to negative potential where hydrogen evolution reaction (HER) takes place. 4 In the present study, we constructed a viologen monolayer on indium tin oxide (ITO), which is a transparent electrode, so that the electron transfer steps at the Pt complex/viologen monolayer system in the HER process can be clarified by monitoring the electrochemically generated viologen species spectroelectrochemically in UV/vis region upon potential step to HER region. …”