performance characterization of a hydrogen peroxide fuel cell with au-electroplated carbon fiber electrode

Exploring Innovative 3D Electrodes for Hydrogen Peroxide Fuel Cells

A fuel cell is an electrochemical device that utilizes fuel and oxidant to convert chemicals into electrical energy. FCs have higher energy conversion efficiency than traditional combustion engines since they are not bound by the Carnot Cycle1. By utilizing fuels such as hydrogen (H2)2, borohydride-hydrogen (NaBH4)3, and ammonia (NH3)4, FCs have become a promising energy source that is environmentally clean and can achieve high performance, offering significant potential to reduce human dependence on fossil fuels. However, FC technology faces specific challenges. One prevalent issue is the internal role of a proton exchange membrane (PEM) in the FC system, which acts as a safeguard against internal short circuits. The integration of an electrolytic membrane contributes to increased fabrication costs, internal circuit resistance, and architectural complexity5. Moreover, transforming single-compartment FCs into multi-stack arrays introduces additional complications due to the intricate process of integrating flow channels, electrodes, and plates to enhance power and current outputs5.
Over the past decades, concerted efforts have been made to address these membrane-related challenges and streamline the FC system. Notably, the emergence of membraneless FC configurations using laminar co-flows at low Reynold numbers has offered an innovative solution. In such setups, the interface between two flows functions as a &#34;virtual&#34; proton-conducting membrane6. Laminar flow-based FCs (LFFCs) have been widely studied, leveraging the benefits of microfluidics7,8,9,10. However, LFFCs require stringent conditions, including high energy input for pumping laminar fuels/oxidants, mitigation of reactant crossover in fluidic streams, and optimization of hydrodynamic parameters.
Recently, H2O2 has gained interest as a potential fuel and oxidant due to its carbon-neutral nature, yielding water (H2O) and oxygen (O2) during electrooxidation and electroreduction processes at electrodes11,12. H2O2 can be mass-produced using a two-electron reduction process or by a two-electron oxidation process from water12. Subsequently, in contrast to other gaseous fuels, liquid H2O2 fuel can be integrated into existing gasoline infrastructure 5. Besides, the H2O2 disproportionation reaction makes it possible to serve H2O2 as both fuel and oxidant. Figure 1A shows a schematic structure of a facile H2O2 FC&#39;s architecture. In comparison to traditional FCs2,3,4, the H2O2 FC utilizes the advantages of device &#34;simplicity.&#34; Yamasaki et al. demonstrated membraneless H2O2 FCs, playing the role of both fuel and oxidant. The described mechanism of electrical energy generation has inspired research communities to continue this research direction6. Subsequently, electrooxidation and electroreduction mechanisms using H2O2 as a fuel and oxidant have been represented by the following reactions13,14
In the acidic media:
Anode: H2O2 &#8594; O2 + 2H+ + 2e-; Ea1 = 0.68 V vs. SHE 
Cathode: H2O2 + 2H+ + 2e- &#8594; 2H2O; Ea2 = 1.77 V vs. SHE 
Total: 2 H2O2 &#8594; 2H2O + O2
In the basic media:
H2O2 + OH- &#8594; HO2- + H2O 
Anode: HO2- + OH- &#8594; O2 + H2O + 2e-; Eb1 = 0.15 V vs. SHE 
Cathode: HO2- + H2O + 2e- &#8594; 3OH-; Eb2 = 0.87 V vs. SHE 
Total: 2 H2O2 &#8594; 2H2O + O2
Figure 1B illustrates the working principle of H2O2 FCs. H2O2 donates electrons at the anode and accepts electrons at the cathode. Electron transfer between the anode and cathode occurs through an external circuit, resulting in the generation of electricity. The theoretical open circuit potential (OCP) of H2O2 FC is 1.09 V in acidic media and 0.62 V in basic media13. However, numerous experimental results have shown lower values, reaching up to 0.75 V in acidic media and 0.35 V in basic media, compared to the theoretical OCP. This observation can be attributed to the presence of a mixed potential13. Additionally, the power and current output of H2O2 FCs cannot compete with the mentioned FCs2,3,4due to the limited catalytic selectivity of the electrodes. Nevertheless, it is noteworthy that current H2O2 FC technology can outperform H2, NaBH4, and NH3 FCs in terms of overall cost, as shown in Table 1. Thus, the enhanced catalytic selectivity of electrodes for H2O2 electrooxidation and electroreduction remains a significant challenge for these devices.
In this study, we introduce a three-dimensional porous structure electrode to improve the interaction between the electrode and H2O2 fuel, aiming to increase the reaction rate and enhance power and current output. We also investigate the impact of solution pH and H2O2 concentration on the FC&#39;s performance. The electrode pair used in this study comprises a gold-electroplated carbon fiber cloth and nickel foam. Structural characterization is conducted using X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM), with Open Circuit Potential (OCP), polarization, and power output curves serving as the primary parameters for FC testing.

Author Spotlight: Design and Evaluation of Au-Electroplated Carbon Fiber Cloth Electrodes for Hydrogen Peroxide Fuel Cells 

Membraneless Hydrogen Peroxide Fuel Cells as a Promising Clean Energy Source

We have illustrated a facial electroplating method deposit nano gold particles on the high surface area carbon cloth. The golds electroplate carbon cloth is heavy grid performance in serving as a cathode for hydrogen peroxide fuel cells. Due to the specific mechanism of membraneless hydrogen peroxide fuel cells, researchers are currently based on developing noble metal complexes as electrodes and improving the sensitive area of these electrodes by employing nanotechnology and coordination chemistry.In our research, we not only proposed the electroplating methods for fabrication high surface area for the electrodes, but also found a very important role of pH in fuel cell, which remains neglected in the previously reported research. There are a lot of techniques can be used for fabricating these nanoscale electrodes, such as physical or chemical evaporations. However, this methods are very expensive, as well as time consuming.As electrodes now need accuracy in thickness, electroplating is a very promising methods for these electrodes.

Watch this Scientific Journal Video about Performance Characterization of a Hydrogen Peroxide Fuel Cell with Au-Electroplated Carbon Fiber Electrode at JoVE.com

Performance Characterization of a Hydrogen Peroxide Fuel Cell with Au-Electroplated Carbon Fiber Electrode  

To begin, prepare two sets of hydrogen peroxide solutions. One set of solutions for pH gradient composed of 1 molar hydrogen peroxide having variable pH while the other set for concentration gradient composed of varying concentrations of hydrogen peroxide at pH 1. To characterize the fuel cell or FC performance by the electrochemical station or ES, first, wash the nickel foam and gold electroplated carbon fiber cloth electrodes with deionized water two times and place them aside.For obtaining the open circuit potential or OCP data, use nickel foam as both RE and CE, and the gold electroplated carbon fiber cloth as the working electrode or WE.Next, add the appropriate hydrogen peroxide solution previously prepared to the test beaker. Connect electrodes to the ES before turning on the system. Set the program to open circuit potential time method, the run time to 400 seconds, the sample interval to 0.1 seconds, the high E limit to 1 volt, and the low E limit to 1 volt.Run the program to measure the data, after that, close the program. To test the output performance of FC based on OCP data, set the program to LSV, OCP as initial E, and 0 volt is final E, corresponding to the conditions of open circuit and short circuit respectively. Run the program to collect the data.Once done, close the program. Wash the beaker and electrodes before adding other required solutions for specific tests. After the experiments are complete, store the washed electrodes in a glass or plastic box.The OCP durability of the FC determined that different hydrogen peroxide concentrations with a pH of 1 indicated that, in all cases, the electrode could operate continuously for at least 400 seconds without significant degradation. The FC performance was found to be sensitive to the solution pH. Under extreme acidic and basic conditions, the power output of the FC was relatively high.

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397 Aufrufe.  Fudan University. Bereiten Sie zunächst zwei Sätze Wasserstoffperoxidlösungen vor. Ein Satz von Lösungen für den pH-Gradienten besteht aus 1 molaren Wasserstoffperoxid mit variablem pH-Wert, während der andere Satz für einen Konzentrationsgradienten aus unterschiedlichen Konzentrationen von Wasserstoffperoxid bei pH 1 besteht. Um die Leistung der Brennstoffzelle oder des FC durch die elektrochemische Station oder ES zu charakterisieren, waschen Sie zunächst die Elektroden aus Nickelschaum und goldgalva...