An optimized nickel phosphate/carbon composite electrocatalyst for the oxidation of formaldehyde
| Autor: | Ahmed H. Touny, Ibrahim Elghamry, Mamdouh E. Abdelsalam, Samya A. Al-Jendan, Mahmoud M. Saleh, Wafa Shamsan Al-Arjan |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Materials science
Renewable Energy Sustainability and the Environment Energy Engineering and Power Technology chemistry.chemical_element 02 engineering and technology Chronoamperometry 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics Electrocatalyst 01 natural sciences 0104 chemical sciences Dielectric spectroscopy Catalysis Nickel Fuel Technology Adsorption chemistry Specific surface area Cyclic voltammetry 0210 nano-technology Nuclear chemistry |
| Zdroj: | International Journal of Hydrogen Energy. 45:14320-14333 |
| ISSN: | 0360-3199 |
| DOI: | 10.1016/j.ijhydene.2020.03.141 |
| Popis: | The electrocatalytic performance of highly conducting Nickel phosphate (NiPh)/carbon composite catalyst is investigated for the oxidation of formaldehyde in alkaline solution. The NiPh nanoparticles are synthesized by a cost-effective one-pot method, which is based on refluxing nickel and phosphate precursors at 90 °C. Inks of the composite catalyst are produced by mixing NiPh nanoparticles with carbon conductive additives (CCA) and Nafion oil. Then, the ink is cast then dried on the glassy carbon electrode. Systematic study is performed to investigate the effect of varying the CCA loading on the electrochemical oxidation of formaldehyde. The best catalytic performance is obtained for NiPh/CCA composite catalyst containing 20 wt% of CCA (NiPh/CCA-20 wt%). The physicochemical properties of the composite catalysts are investigated and analyzed by field-emission scanning electron microscopy (FE-SEM), Energy Dispersive x-ray Spectroscopy (EDX) and X-ray diffraction (XRD). Also, the N2 adsorption/desorption isotherms are recorded and the Brunauer–Emmett–Teller (BET) and Barrett-Joyner-Halenda (BJH) methods are used to calculate the specific surface area and pore size distribution. The electrocatalytic performance of the NiPh/CCA composite was compared to the pristine NiPh for the oxidation of formaldehyde in alkaline solution. Electrochemical impedance spectroscopy technique is used to study the electrical conductivity of the composite catalysts. Additionally, cyclic voltammetry and chronoamperometry techniques are used to calculate key parameters such as surface coverage (Γ) of Ni2+/Ni3+ species, the diffusion coefficient of the formaldehyde (D) and the catalytic rate constant (kcat). A, D and kcat values for the NiPh/CCA-20 wt% catalyst are 5.95 × 10−5 mmol cm−2, 1.08 × 10−4 cm2 s−1 and 2.59 × 107 cm3 mol−1 s−1 respectively. Both Γ and kcat parameters are used to identify the optimum composition of the catalyst. |
| Databáze: | OpenAIRE |
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