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Updated: Jun 12, 2026

Hydrogen Production and Utilization in a Membrane Reactor
Published on: March 10, 2023
Switching Hydrogen Transfer Pathway Over Paddle-Wheel Dicopper Molecular Catalysts for Efficient Electrocatalytic
Rui Bai1, Jin Lin1, Chang Liu1
1State Key Laboratory of Solidification Processing and School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an, P. R. China.
None:
Elucidating the hydrogen transfer pathway of electrocatalytic acetylene semihydrogenation (EAH) is crucial for understanding the catalytic mechanism and designing high-performance catalysts, but faces grand challenges. Herein, we unprecedentedly switch the hydrogen transfer pathway between Eley-Rideal mechanism and Langmuir-Hinshelwood mechanism over paddle-wheel dicopper molecular catalysts, where the charge density of the Cu sites is effectively modulated by the ligands with different electron-withdrawing ability. Extended X-ray absorption fine structure (EXAFS), operando characterizations, and theoretical calculations together reveal that the moderate charge density of Cu sites in benzoic acid-Cu catalyst (BA-Cu) inhibits H2O dissociation and reduces C2H2 adsorption energy, promoting the co-adsorption of C2H2 and H2O and steering the EAH through the Eley-Rideal mechanism. In acetic acid-Cu (AA-Cu) with low charge density and monofluorobenzoic acid-Cu (MFBA-Cu) with high charge density, the Cu sites facilitate H2O dissociation to *H and hydrogenate C2H2 via the Langmuir-Hinshelwood mechanism. In 1 M KOH aqueous solution, the BA-Cu delivers an ethylene partial current density of 328 mA/cm2 with an ethylene Faradaic efficiency (FE) of 96.4% at -0.9 V versus RHE, which is about 2-fold and 1.4-fold higher than AA-Cu and MFBA-Cu. This work provides mechanistic insights for the rational design of high-performance electrocatalysts by regulating the hydrogenation kinetics.
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