Status : Verified
| Personal Name | Dumlao, Alicia Theresse G. |
|---|---|
| Resource Title | Porous and bifunctional Ni-P catalyst electrodes for alkaline water electrolysis synthesized from a template-free method |
| Date Issued | 9 January 2025 |
| Abstract | In order to fully realize the potential of water electrolysis in the transition to sustainable energy systems, catalysts that counter the slow kinetics of the H2 evolution reaction (HER) in the cathode and the O2 evolution reaction (OER) in the anode are needed. Among the emerging materials, transition metal phosphide (TMP) catalysts have promising activity and stability in HER and OER. In particular, nickel phosphides perform well as electrocatalysts due to their efficient electron transfer between the transition metal and phosphorus sites. Nickel phosphides can be prepared through various synthesis methods. One of them is the emerging technique, the dynamic H2 bubble template (DHBT) method, a facile and dynamic technique that can yield porous morphologies with numerous active sites. This work investigated the applied potential and phosphorus source (NaH2PO2) concentration parameters for DHBT to fabricate porous, active, and stable OER and HER Ni-P catalysts. Among the samples, NiP-500, which was synthesized with an applied potential of -4 V vs. Ag/AgCl and a NaH2PO2 concentration of 500 mM, yielded the best electrochemical performance for alkaline water electrolysis. It only required a low overpotential at 10 mA cm- of 265 mV for OER and 154 mV for HER. NiP-500 also exhibited good kinetics, with low Tafel slopes and charge transfer resistances for both reactions. Moreover, the catalyst exhibited minimal change in overpotential even after 12 hours of high-current density operation. Specifically, NiP-500 only had 2.93% and 2.72% increases for OER and HER, respectively. These good catalytic properties were brought upon by the catalyst’s semi-crystalline structure, porous morphology, and tuned composition, which were observed through various materials characterization methods. Further evaluation of the Ni-P catalyst’s bifunctionality as water electrolyzer anode and cathode also yielded promising results, registering a low cell potential of 1.64 V at 10 mA cm-2 |
| Degree Course | Master of Science in Energy Engineering |
| Language | English |
| Keyword | Water electrolysis, DHBT synthesis, nickel phosphide, OER, HER |
| Material Type | Thesis/Dissertation |
Preliminary Pages
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Category : F - Regular work, i.e., it has no patentable invention or creation, the author does not wish for personal publication, there is no confidential information.
Access Permission : Open Access