TY  - JOUR
A1  - Neumann, Bettina
A1  - Götz, Robert
A1  - Wrzolek, Pierre
A1  - Scheller, Frieder W.
A1  - Weidinger, Inez M.
A1  - Schwalbe, Matthias
A1  - Wollenberger, Ulla
T1  - Enhancement of the Electrocatalytic Activity of Thienyl-Substituted Iron Porphyrin Electropolymers by a Hangman Effect
JF  - ChemCatChem : heterogeneous & homogeneous & bio- & nano-catalysis ; a journal of ChemPubSoc Europe
N2  - The thiophene-modified iron porphyrin FeT3ThP and the respective iron Hangman porphyrin FeH3ThP, incorporating a carboxylic acid hanging group in the second coordination sphere of the iron center, were electropolymerized on glassy carbon electrodes using 3,4-ethylenedioxythiophene (EDOT) as co-monomer. Scanning electron microscopy images and Resonance Raman spectra demonstrated incorporation of the porphyrin monomers into a fibrous polymer network. Porphyrin/polyEDOT films catalyzed the reduction of molecular oxygen in a four-electron reaction to water with onset potentials as high as +0.14V vs. Ag/AgCl in an aqueous solution of pH7. Further, FeT3ThP/polyEDOT films showed electrocatalytic activity towards reduction of hydrogen peroxide at highly positive potentials, which was significantly enhanced by introduction of the carboxylic acid hanging group in FeH3ThP. The second coordination sphere residue promotes formation of a highly oxidizing reaction intermediate, presumably via advantageous proton supply, as observed for peroxidases and catalases making FeH3ThP/polyEDOT films efficient mimics of heme enzymes.
KW  - activation of oxygen species
KW  - electro-polymerization
KW  - Hangman porphyrin
KW  - heterogeneous catalysis
KW  - immobilization
Y1  - 2018
U6  - https://doi.org/10.1002/cctc.201800934
SN  - 1867-3880
SN  - 1867-3899
VL  - 10
IS  - 19
SP  - 4353
EP  - 4361
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Cui, Qianling
A1  - Shen, Guizhi
A1  - Yan, Xuehai
A1  - Li, Lidong
A1  - Moehwald, Helmuth
A1  - Bargheer, Matias
T1  - Fabrication of Au@Pt multibranched nanoparticles and their application to in situ SERS monitoring
JF  - ACS applied materials & interfaces
N2  - Here, we present an Au@Pt core-shell multibranched nanoparticle as a new substrate capable of in situ surface-enhanced Raman scattering (SERS), thereby enabling monitoring of the catalytic reaction on the active surface. By careful control of the amount of Pt deposited bimetallic Au@Pt, nanoparticles with moderate performance both for SERS and catalytic activity were obtained. The Pt-catalyzed reduction of 4-nitrothiophenol by borohydride was chosen as the model reaction. The intermediate during the reaction was captured and clearly identified via SERS spectroscopy. We established in situ SERS spectroscopy as a promising and powerful technique to investigate in situ reactions taking place in heterogeneous catalysis.
KW  - nanoparticles
KW  - gold
KW  - core-shell nanostructure
KW  - surface-enhanced Raman scattering
KW  - heterogeneous catalysis
KW  - bimetallic nanoparticles
Y1  - 2014
U6  - https://doi.org/10.1021/am504709a
SN  - 1944-8244
VL  - 6
IS  - 19
SP  - 17075
EP  - 17081
PB  - American Chemical Society
CY  - Washington
ER  -