Aqueous-phase oxygen evolution reaction (OER) is the bottleneck of water splitting. The formation of the O−O bond involves the generation of paramagnetic oxygen molecules from the diamagnetic hydroxides. The spin configurations might play an important role in aqueous-phase molecular electrocatalysis. However, spintronic electrocatalysis is almost an uncultivated land for the exploration of the oxygen molecular catalysis process. Herein, we present a novel magnetic Fe III site spin-splitting strategy, wherein the electronic structure and spin states of the Fe III sites are effectively induced and optimized by the Jahn−Teller effect of Cu 2+ . The theoretical calculations and operando attenuated total reflectance-infrared Fourier transform infrared (ATR FT-IR) reveal the facilitation for the O−O bond formation, which accelerates the production of O 2 from OH − and improves the OER activity. The Cu 1 −Ni 6 Fe 2 −LDH catalyst exhibits a low overpotential of 210 mV at 10 mA cm −2 and a low Tafel slope (33.7 mV dec −1 ), better than those of the initial Cu 0 −Ni 6 Fe 2 −LDHs (278 mV, 101.6 mV dec −1 ). With the Cu 2+ regulation, we have realized the transformation of NiFe−LDHs from ferrimagnets to ferromagnets and showcase that the OER performance of Cu−NiFe−LDHs significantly increases compared with that of NiFe−LDHs under the effect of a magnetic field for the first time. The magnetic-fieldassisted Cu 1 −Ni 6 Fe 2 −LDHs provide an ultralow overpotential of 180 mV at 10 mA cm −2 , which is currently one of the best OER performances. The combination of the magnetic field and spin configuration provides new principles for the development of highperformance catalysts and understandings of the catalytic mechanism from the spintronic level.
A transition-metal-free approach was disclosed for intermolecular aryl C-N bonds formation between phenols and cyclic anilines via cross-dehydrogenative coupling (CDC) amination that was mediated by visible light, wherein K2S2O8 served as an external oxidant. The salient features of this protocol include circumventing the requirement for prefunctionalized starting materials and achieving single regioselectivity of amination adducts at room temperature.
The
direct intermolecular aryl C–N coupling reaction from
precursors without preactivated C–H and N–H bonds has
been challenging. Herein, an oxidative system combining a catalytic
amount of organic photocatalyst with stoichiometric amount of persulfate
was developed to enable the successful cross-dehydrogenative-coupling
amination between phenols and acyclic diarylamines in a nonmetallic
method. This protocol precludes both coupling partners from prefunctionalization
and achieved single regioselectivity of amination products under genuinely
simple and benign conditions. Broad scopes of substrates were evaluated
with moderate to high efficacy, and the reaction efficiency of electron-deficient
phenothiazine and phenol was highly improved. A radical/radical cross-coupling
pathway was proposed based on mechanistic studies, wherein a radical
chain propagation process was involved.
A visible-light-enabled, iron-catalyzed three-component reaction for difunctionalization of alkenes with amines and diselenides has been developed, wherein a photo-excitable Fe-amine complex is proposed as the key intermediate.
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