2026-10-07T02:28:20Z https://api.figshare.com/v2/oai

oai:figshare.com:article/33872167 2026-09-17T05:55:50Z category_37 portal_316 item_type_3 month_year_09_2026

Data Sheet 1_Hierarchically porous Co–N–C catalysts from bimetallic Zn/Co zeolitic imidazolate frameworks for selective CO2 electroreduction to CO.pdf Zhaoyu Meng (25002325) Organic Chemistry Co–Nx sites Co–N–C electrochemical CO2 reduction hierarchical porous carbon metal–organic frameworks zeolitic imidazolate framework <p>The conversion of CO₂ to CO using electrochemistry requires the use of earth abundant catalysts with high selectivity, rapid reaction rate, and durability. In this work, hierarchically porous Co–N–C catalysts were synthesized via co-pyrolysis of a bimetallic zeolitic imidazolate framework (Zn/Co) and the dicyandiamide (DCD) followed by acid etching. By systematically adjusting the pyrolysis temperature (800 °C–1,000 °C) and the Co feed ratio (5–20 mol%), volcano-type activity relationships are found, which are controlled by the interplay of the three factors graphitization, nitrogen retention, and the density of Co–N_x sites. The optimized catalyst CoNC-900 achieves a Faradaic efficiency of CO of 94.9% ± 1.0% at −0.75 V vs. RHE in CO₂-saturated 0.5 M KHCO₃ with a CO partial current density of 16.0 mA cm⁻², a lower bound turnover frequency of ≥0.33 s⁻¹ and ≈11% current decay FE_CO retained above 92% over 24 h. The observed selectivity can be rationalized, as the density functional theory calculations indicate that the barrier of the rate-determining step, namely the formation of COOH is lowered on the Co–N₄ moiety (0.42 eV, whereas ≥1.79 eV on the metal-free nitrogen sites). A transferable design rule is developed for CO₂ electrolysis that relates bimetallic MOF precursor chemistry, hierarchical porosity, and M–N_x site engineering.</p> 2026-09-17T05:55:50Z Dataset Dataset 10.3389/fchem.2026.1940515.s001 https://figshare.com/articles/dataset/Data_Sheet_1_Hierarchically_porous_Co_N_C_catalysts_from_bimetallic_Zn_Co_zeolitic_imidazolate_frameworks_for_selective_CO2_electroreduction_to_CO_pdf/33872167 CC BY 4.0