2026-10-12T01:54:59Z https://api.figshare.com/v2/oai

oai:figshare.com:article/34029672 2026-09-30T04:47:46Z category_621 portal_316 item_type_3 month_year_09_2026

Table 1_Decoupling bulk composition and alloying effects in Ni-Mo materials for electrocatalytic hydrogen evolution at near-neutral pH.docx Shabnam Pouresmaeil (25141503) Andrea Prager (3245637) Jan Griebel (1738645) Falk Harnisch (841708) Jörg Kretzschmar (8997234) Energy Generation, Conversion and Storage Engineering hydrogen evolution reaction mass loading microbial electrosynthesis nominal composition phase structure <p>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.</p> 2026-09-30T04:47:46Z Dataset Dataset 10.3389/fenrg.2026.1939600.s002 https://figshare.com/articles/dataset/Table_1_Decoupling_bulk_composition_and_alloying_effects_in_Ni-Mo_materials_for_electrocatalytic_hydrogen_evolution_at_near-neutral_pH_docx/34029672 CC BY 4.0