TY - JOUR
T1 - Gas flow stimulated hydrodynamics for preparation and application of platinized titanium hollow fibre electrodes
AU - Jong, Ronald P.H.
AU - Mul, Guido
N1 - Funding Information:
R. P. H. Jong acknowledges financial support from the NWO financed Graduate Research Program on Solar Fuels. Furthermore, we acknowledge the hollow fibre team at the University of Twente, including; Anne C. Sustronk, Liniker F. de Sousa, Piotr M. Krzywda and Nieck E. Benes, for fruitful discussions.
Funding Information:
R. P. H. Jong acknowledges financial support from the NWO financed Graduate Research Program on Solar Fuels. Furthermore, we acknowledge the hollow fibre team at the University of Twente, including; Anne C. Sustronk, Liniker F. de Sousa, Piotr M. Krzywda and Nieck E. Benes, for fruitful discussions.
Publisher Copyright:
© 2022 The Authors. ChemElectroChem published by Wiley-VCH GmbH
PY - 2022/3/11
Y1 - 2022/3/11
N2 - In this study, Pt was electrodeposited on the surface of Ti hollow fibres from PtCl62- solution at fixed potential and at variable gas flow rate. Partial Pt coverage of Ti was obtained at flow rates ≤ 5 mL∙min-1, while a more-even geometrical distribution and linearly increasing Electrochemical Surface Area (ECSA) of Pt was obtained for flow rates of > 5 and < 20 mL∙min-1. Above 20 mL∙min-1, the morphology did not significantly change, and only a limited increase in ECSA of Pt (PtECSA) was obtained. Second, the performance of the Pt functionalized Ti-HFEs was evaluated at fixed potential in i) liquid phase oxidation of FeII to FeIII, and ii) the hydrogen (gas) evolution reaction (HER). Generally, for the oxidation of Fe(CN)64-, a linear increase in current from 3 to ~9 mA was found as a function of increasing gas flow. For the HER, a gas evolving reaction, initially (in the range of 0 – 10 mL.min-1) a much larger enhancement in current (from ~-10 to -35 mA) was observed than consecutively at higher flow rates. The effect of gas flow rate on Pt deposition, and utilization of platinized Ti HFEs, is explained on the basis of increasing fractional participation of relatively small pores at high flow rates, and generally an increasing mass transfer coefficient (kM) associated with localized mixing of the electrolyte near the electrode/electrolyte interface. The kM is roughly in the same order of magnitude as obtained in experiments using rotating disc electrodes.
AB - In this study, Pt was electrodeposited on the surface of Ti hollow fibres from PtCl62- solution at fixed potential and at variable gas flow rate. Partial Pt coverage of Ti was obtained at flow rates ≤ 5 mL∙min-1, while a more-even geometrical distribution and linearly increasing Electrochemical Surface Area (ECSA) of Pt was obtained for flow rates of > 5 and < 20 mL∙min-1. Above 20 mL∙min-1, the morphology did not significantly change, and only a limited increase in ECSA of Pt (PtECSA) was obtained. Second, the performance of the Pt functionalized Ti-HFEs was evaluated at fixed potential in i) liquid phase oxidation of FeII to FeIII, and ii) the hydrogen (gas) evolution reaction (HER). Generally, for the oxidation of Fe(CN)64-, a linear increase in current from 3 to ~9 mA was found as a function of increasing gas flow. For the HER, a gas evolving reaction, initially (in the range of 0 – 10 mL.min-1) a much larger enhancement in current (from ~-10 to -35 mA) was observed than consecutively at higher flow rates. The effect of gas flow rate on Pt deposition, and utilization of platinized Ti HFEs, is explained on the basis of increasing fractional participation of relatively small pores at high flow rates, and generally an increasing mass transfer coefficient (kM) associated with localized mixing of the electrolyte near the electrode/electrolyte interface. The kM is roughly in the same order of magnitude as obtained in experiments using rotating disc electrodes.
KW - Electrodeposition
KW - holow fiber electrode
KW - titanium
KW - Mass transfer enhancement
KW - Hydrogen evolution
KW - electrochemical surface area
KW - electrochemical engineering
KW - Pore size distribution
KW - Pore size
KW - UT-Hybrid-D
U2 - 10.1002/celc.202101135
DO - 10.1002/celc.202101135
M3 - Article
SN - 2196-0216
VL - 9
JO - ChemElectroChem
JF - ChemElectroChem
IS - 5
M1 - e202101135
ER -