The electrochemical reduction of CO to multi-carbon products has attracted much attention because it provides an avenue to the synthesis of value-added carbon-based fuels and feedstocks using renewable electricity. Unfortunately, the efficiency of CO conversion to C products remains below that necessary for its implementation at scale. Modifying the local electronic structure of copper with positive valence sites has been predicted to boost conversion to C products. Here, we use boron to tune the ratio of Cu to Cu active sites and improve both stability and C-product generation. Simulations show that the ability to tune the average oxidation state of copper enables control over CO adsorption and dimerization, and makes it possible to implement a preference for the electrosynthesis of C products. We report experimentally a C Faradaic efficiency of 79 ± 2% on boron-doped copper catalysts and further show that boron doping leads to catalysts that are stable for in excess of ~40 hours while electrochemically reducing CO to multi-carbon hydrocarbons.
N fixation by the electrocatalytic nitrogen reduction reaction (NRR) under ambient conditions is regarded as a potential approach to achieve NH production, which still heavily relies on the Haber-Bosch process at the cost of huge energy and massive production of CO . A noble-metal-free Bi V O /CeO hybrid with an amorphous phase (BVC-A) is used as the cathode for electrocatalytic NRR. The amorphous Bi V O contains significant defects, which play a role as active sites. The CeO not only serves as a trigger to induce the amorphous structure, but also establishes band alignment with Bi V O for rapid interfacial charge transfer. Remarkably, BVC-A shows outstanding electrocatalytic NRR performance with high average yield (NH : 23.21 μg h mg , Faradaic efficiency: 10.16 %) under ambient conditions, which is superior to the Bi V O /CeO hybrid with crystalline phase (BVC-C) counterpart.
Copper-based materials are promising electrocatalysts for CO2 reduction. Prior studies show that the mixture of copper (I) and copper (0) at the catalyst surface enhances multi-carbon products from CO2 reduction; however, the stable presence of copper (I) remains the subject of debate. Here we report a copper on copper (I) composite that stabilizes copper (I) during CO2 reduction through the use of copper nitride as an underlying copper (I) species. We synthesize a copper-on-nitride catalyst that exhibits a Faradaic efficiency of 64 ± 2% for C2+ products. We achieve a 40-fold enhancement in the ratio of C2+ to the competing CH4 compared to the case of pure copper. We further show that the copper-on-nitride catalyst performs stable CO2 reduction over 30 h. Mechanistic studies suggest that the use of copper nitride contributes to reducing the CO dimerization energy barrier—a rate-limiting step in CO2 reduction to multi-carbon products.
In view of the sluggish kinetics suppressing the oxygen evolution reaction (OER), developing efficient and robust OER catalysts is urgent and essential for developing efficient energy conversion technologies. Herein, hybrid amorphous/crystalline FeCoNi layered double hydroxide (LDH)‐supported single Ru atoms (Ru SAs/AC‐FeCoNi) are developed for enabling a highly efficient electrocatalytic OER. The amorphous outer layer in Ru SAs/AC‐FeCoNi is composed of abundant defect sites and unsaturated coordination sites, which can serve as anchoring sites to stabilize single Ru atoms. The crystalline inner has a highly symmetric rigid structure, thereby strengthening the stability of support for a long‐lasting OER. The synergistic effects endow this hybrid catalyst with extremely low overpotential (205 mV at 10 mA cm−2). Density functional theory calculation indicates that single Ru atoms stabilized by hybrid amorphous/crystalline FeCoNi LDH facilitate the formation of Ru–O* (rate‐determining step), thus accelerating the OER process.
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