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Presently, realizing high ethanol selectivity in CO2electroreduction remains challenging due to difficult C–C coupling and fierce product competition. In this work, we report an innovative approach for improving the efficiency of Cu-based electrocatalysts in ethanol generation from electrocatalytic CO2reduction using a crystal plane modification strategy. These novel Cu-based electrocatalysts were fabricated by electrochemically activating three-dimensional (3D) flower-like CuO micro/nanostructures grown in situ on copper foils and modifying with surfactants. It was demonstrated that the fabricated Cu-based electrocatalyst featured a predominantly exposed Cu(100) surface loaded with high-density Cu nanoparticles (NPs). The optimal Cu-based electrocatalyst displayed considerably improved CO2electroreduction performance, with a Faraday efficiency of 37.9% for ethanol and a maximum Faraday efficiency of 68.0% for C2+products at −1.4 V vs RHE in an H-cell, accompanied by a high current density of 69.9 mA·cm–2, much better than the particulate Cu-based electrocatalyst. It was unveiled that the Cu(100)-rich surface of nanoscale petals with abundant under-coordinated copper atoms from CuNPs was conducive to the formation and stabilization of key *CH3CHO and *OC2H5intermediates, thereby promoting ethanol generation. This study highlighted the critical role of CuNP-loaded Cu(100) surface structures on structured Cu-based electrocatalysts in enhancing ethanol production for the CO2electroreduction process.

Currently, the depletion of fossil fuels has become a pressing issue for society, and one potential solution is the conversion of ethanol, a vital biomass derivative, into high-value chemicals using tandem reactions based on anaerobic dehydrogenation processes. Here, we developed a new copper nanocatalyst supported on a defect-rich MnOxmatrix, fabricated by a modified coprecipitation method using a microliquid-film (MLF) reactor. By enhancing the micromixing of Mn and Cu ions in the synthesis solution, the use of the MLF reactor promoted the dispersion of copper particles with favorable interfacial Cu+–O–Mn structures and the formation of defect-rich MnOxsupport with abundant oxygen vacancies. The as-fabricated Cu/MnOxcatalyst delivered a higher yield of acetaldehyde and greater structural stability, compared to two Cu-based catalysts produced using traditional impregnation and coprecipitation methods. Surface defective oxygen vacancies and interfacial Cu+–O–Mn structures were found to effectively facilitate the activation adsorption of ethanol and stabilize the formed ethoxy intermediate, improving the dehydrogenation of ethanol to produce acetaldehyde. This work presents a novel synthesis strategy for supported metal catalysts, which enables the creation of active surface-interface structures, resulting in exceptional catalytic properties for use in various advanced catalytic processes.

Currently, Fe-based catalysts show excellent catalytic performance in the hydrogenation of CO2to produce light olefins. Despite numerous studies, the identification of the role of catalytically active components over Fe-based catalysts for CO2hydrogenation is not quite clear. In this work, a series of ZrO2-supported cobalt-doped Fe-based catalysts were fabricated by a microliquid film reactor-assisted coprecipitation method. It was demonstrated that appropriately strong interactions between Fe-containing species and the ZrO2support in catalyst precursors could facilitate the generation of a defective FeOxcomponent upon reduction treatment and inhibit the carburization of metallic iron during the reaction. Among all Fe-based catalysts, the catalyst bearing a (Co + Fe)/ZrO2mass ratio of 3:7 and a Co/Fe molar ratio of 1:9 achieved a highest light olefins selectivity of about 38% at 49% CO2conversion under reaction conditions (i.e., 320 °C, 2.0 MPa, and 4800 mL·gcat–1·h–1), along with a high Fe time yield to light olefins of 9.2 μmolCO2·gFe–1·s–1and a low CO selectivity of 4.7%. Comprehensive structural characterization and catalytic CO2hydrogenation experiments clarified that the surface-dominant defect-rich FeOxcomponent as catalytically active species substantially played a crucial role in governing the hydrogenation of CO2, mainly owing to their enhanced adsorption and binding ability for CO2and the CO intermediate. This study offers a new strategy to design Fe-based catalysts and provides deep insight into the role of iron oxide species for CO2hydrogenation to produce light olefins.