Highly efficient platinum nanocatalysts synthesized by an open-loop reduction system with a controlled temperature loop

Thickness Control over Ionomer Coatings on Nano Patterned Three-Phase Zones for a Highly Efficient Electrode

“…Using 16.6 mL ethylene glycol (C 2 H 6 O 2 , Shimakyu's Pure Chemicals, Japan) as a reducing agent in 83.4 mL deionized (DI) water, 0.8 mM chloroplatinic acid (H 2 PtCl 6 .6H 2 O, Alfa Aesar, 99.9%), which was used as a Pt catalyst precursor, was reduced at 130 • C for 1 h and 15 min at atmospheric pressure using a home-made chemical reduction system to deposit Pt catalysts on the CNT. 33 The resulting nano patterned Pt/CNT electrodes were gently rinsed with DI water and were dried at 60 • C for 5 min. Finally, a com-mercially available Nafion ionomer (20 wt% solution, DuPont, USA) was dropped onto the hydrophilic-treated Pt/CNT/Si-based electrodes with a micropipette and was spin-coated onto the entire surface of the electrodes to form TPZs.…”

“…Upon further addition of ionomers within the CL, an increase in the CL thickness was observed, and the reported electrode activity was reduced. 31,32 For the Pt particles with CNTs (Pt/CNTs) directly grown on carbon cloth or silicon, 16,33 the implementation of a well-distributed TPZ is usually a difficult task due to the narrow spacing (50-100 nm) among the CNTs. Conventional paste or spray methods would not be able to achieve a full ionomer coverage down to the roots of the CNTs, resulting in an insufficient utilization of the originally well-dispersed catalysts on the CNTs.…”

Enhancement of catalytic efficiency by partial replacement of ruthenium with platinum nanoparticles for direct methanol fuel cell

“…The working principle is to impose a variable voltage at the working electrode (WE) and analyze the current signal received with time to determine the oxidation-reduction (redox) status in the electrochemical reaction. In this case, we imposed time-varying triangular wave of potential in the WE, and then observed the relationship between potential (E, V SCE ) and current density (I, mA/cm 2 ) to realize the potential for the redox reaction, electrochemical mass activity (MA, A/g Pt ) and reaction rate [1,9]. In the CV curves, we can also obtain the active electrochemical surface area (ESA) of Pt catalysts from the hydrogen ion electrosorption reactions (charge transfer density of H + , Q H , mC/cm 2 ) in a H 2 SO 4 aqueous solution.…”

“…Open-loop reduction system (OLRS) was employed to prepare the catalysts of platinum/ruthenium (Pt/Ru) [1]. This system uses water distilling principle to gradually increase the concentration of ethylene glycol (EG) in the chloroplatinic acid solution (platinum precursor) for the reduction of Pt catalyst.…”

“…Among all miniaturized power generation devices, micro fuel cells provide a fast reaction rate, high energy density, and a small volume, etc. Direct methanol fuel cell (DMFC) is easy to accommodate a wide range of fuel supplies, cost effective, simple operation, and less pollution; therefore, it possesses great potential for portable power sources [1]. However, enhancing energy conversion efficiency and power density are important issues for DMFC applications.…”