Boosting hydrogen production by electrochemical benzylamine oxidation through in-situ reconstructed CuCo2O4 catalysts

CuCo 2 O 4 coupled benzylamine oxidation and H₂ evolution with ∼100% efficiency. • Cu accelerates reconstruction, boosts electron transfer, and stabilizes intermediates. • CuCoOOH formation at low potentials promotes dehydrogenation and C N formation. • Surface reconstruction in CuCo 2 O 4 boosts nitrile selectivity and H 2 production. Electrochemical hydrogen production offers a scalable, low-carbon route for clean energy, but its efficiency is constrained by the high energy demand and sluggish kinetics of the oxygen evolution reaction (OER). Replacing OER with anodic oxidation of organic molecules provides a promising approach to reduce energy input while producing value-added chemicals. Here, we demonstrate spinel CuCo 2 O 4 as an efficient electrocatalyst for the selective oxidation of benzylamine to benzonitrile, coupled with hydrogen evolution. CuCo 2 O 4 achieves nearly 100% Faradaic efficiency for both reactions at low potentials (1.35–1.45 V vs RHE), with a maximum benzonitrile yield of 97%, whereas conventional water electrolysis under similar conditions produces negligible hydrogen. By integrating in-situ Raman spectroscopy with density functional theory, we reveal a potential-dependent surface reconstruction mechanism. Specifically, Cu incorporation directs electron transfer from Co to Cu, promoting the formation of a CuCoOOH active phase that enhances benzylamine adsorption and lowers the energy barriers for C–H and N–H dehydrogenation, thereby facilitating C N formation. At higher potentials, however, the formation of Co 4 + -rich phase induces competitive OER, underscoring the critical role of controlling surface phase evolution. Overall, these findings establish a reconstruction-enabled strategy to tailor spinel composition and surface chemistry, positioning CuCo 2 O 4 as a transformative platform for selective organic oxidation coupled with energy-efficient hydrogen production. Download: Download high-res image (187KB) Download: Download full-size image Selective electrocatalytic oxidation of benzylamine to benzonitrile coupled with hydrogen evolution over CuCo 2 O 4 via in situ formation of CuCoOOH active phase