Publication Details |
| Category | Text Publication |
| Reference Category | Journals |
| DOI | 10.3389/fenrg.2026.1939600 |
Licence  |
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| Title (Primary) | Decoupling bulk composition and alloying effects in Ni-Mo materials for electrocatalytic hydrogen evolution at near-neutral pH |
| Author | Pouresmaeil, S.; Prager, A.; Griebel, J.; Harnisch, F.
; Kretzschmar, J. |
| Source Titel | Frontiers in Energy Research |
| Year | 2026 |
| Department | MIBITECH |
| Volume | 14 |
| Page From | art. 1939600 |
| Language | englisch |
| Topic | T7 Bioeconomy |
| Supplements | Supplement 1 Supplement 2 |
| Keywords | hydrogen evolution reaction; mass loading; microbial electrosynthesis; nominal composition; phase structure |
| Abstract | Ni-Mo electrocatalysts are extensively studied for the hydrogen evolution reaction (HER). This includes HER at near-neutral pH conditions relevant to, e.g., microbial electrosynthesis (MES). So far, the role of the Ni:Mo ratio in bulk for determining HER performance remains unclear, especially for commercially available powdery electrocatalysts. Here, we examined commercial Ni-Mo powders with different nominal Ni:Mo ratios to assess how composition and mass loading influence HER performance. Despite differences in bulk Ni:Mo ratios, no significant variation in HER performance was observed at equal mass loadings. In contrast, increasing the electrocatalyst mass loading from 0.35 ± 0.04 to 1.30 ± 0.07 mg cm−2 consistently improved HER performance, decreasing the overpotential at −1 mA cm−2 from 463 ± 50 to 210 ± 9 mV, with an intermediate value of 367 ± 33 mV at a loading of 0.61 ± 0.02 mg cm−2. Comprehensive characterization by XRD, SEM, EDX, and XPS shows that the Ni-Mo powders are not true Ni-Mo alloys but rather physically mixed phases with notable Ni- and Mo-rich segregation. These results demonstrate that the bulk Ni:Mo ratio does not accurately reflect the catalytic structure and hence cannot be used alone to assess structure-function relationships for HER performance. This study underscores the importance of thorough characterization, even of commercial electrocatalysts, and highlights the significance of surface structure over nominal bulk composition for Ni-Mo-based HER electrocatalysts. |
| Pouresmaeil, S., Prager, A., Griebel, J., Harnisch, F., Kretzschmar, J. (2026): Decoupling bulk composition and alloying effects in Ni-Mo materials for electrocatalytic hydrogen evolution at near-neutral pH Front. Energy Res. 14 , art. 1939600 10.3389/fenrg.2026.1939600 |
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