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Achieving efficient efficiency and selectivity for the electroreduction of CO2 to value‐added feedstocks has been challenging, due to the thermodynamic stability of CO2 molecules and the competing hydrogen evolution reaction. Herein, a dual‐single‐atom catalyst consisting of atomically dispersed CuN4 and NiN4 bimetal sites is synthesized with electrospun carbon nanofibers (CuNi‐DSA/CNFs). Theoretical and experimental studies reveal the strong electron interactions induced by the electronegativity offset between the Cu and Ni atoms. The delicately averaged and compensated electronic structures result in an offset effect that optimizes the adsorption strength of the *COOH intermediate and boosts the CO2 reduction reaction (CO2RR) kinetics, notably promoting the intrinsic activity and selectivity of the catalyst. The CuNi‐DSA/CNFs catalyst exhibits an outstanding FECO of 99.6% across a broad potential window of −0.78– −1.18 V (vs the reversible hydrogen electrode), a high turnover frequency of 2870 h–1, and excellent durability (25 h). Furthermore, an aqueous Zn‐CO2 battery for CO2 power conversion is constructed. This atomic‐level electronegativity offset of the dual‐atom structures provides an appealing direction to develop advanced electrocatalysts for the CO2RR. [ABSTRACT FROM AUTHOR]

A simple strategy is developed for synthesis of PdCu nanoplates as efficient ORR electrocatalysts with simultaneously highly methanol tolerance. [Display omitted] The methanol-poisoning of electrocatalysts at the cathodic part of direct methanol fuel cells (DMFCs) can severely degrade the overall efficiency. Therefore, engineering cathodic catalysts with outstanding oxygen reduction activity, and simultaneously, superior methanol tolerance is greatly desired. Herein, bimetallic palladium-copper (PdCu) nanoplates with the optimized d-band center are designed as promising cathodic catalysts for DMFCs. It shows outstanding oxygen reduction activity with a mass activity (MA) of 0.522 A mg Pd −1 in alkaline electrolyte, overwhelming the benchmarked commercial Pt/C and Pd/C. Meanwhile, it has prominent stability with only 4.0 % loss in MA after continuous 20 K cycles. More importantly, the PdCu nanoplates are almost inert toward methanol oxidation and show excellent anti-methanol capability. The theoretical calculations reveal that the downshift of d-band center in PdCu nanoplates and the electronic interaction between Pd and Cu atoms could effectively lower the methanol adsorption energy, thus leading to enhanced methanol tolerance. This work highlights the important role of tuning the electronic structure and optimized geometry of electrocatalysts to simultaneously boost their oxygen reduction activity, stability, and methanol tolerance for their future application in DMFCs. [ABSTRACT FROM AUTHOR]

[Display omitted] A novel strategy is developed for controlled synthesis of hyper-dendritic PdZn nanocrystals as efficient bifunctional electrocatalysts toward ORR and EOR. • A novel strategy is developed for synthesis of hyper-dendritic PdZn nanocrystals. • The HD-PdZn NCs have ample pores, hyper-dendritic morphology and electron effect. • The HD-PdZn NCs exhibit enhanced ORR and EOR activity and durability. • DFT calculation proved that the reduction of OOH* to OH* is accelerated during ORR. Although attentions have been devoted to developing Pd-based bimetallic nanocrystals towards the electrocatalytic oxygen reduction reaction (ORR) and ethanol oxidation reaction (EOR), the engineering of efficient bifunctional electrocatalysts with high atomic utilization still faces big challenges. Herein, we reported a facile one-pot template-free route to fabricate three-dimension hyper-dendritic PdZn nanocrystals (HD-PdZn NCs) that regulated by gas mixtures of carbon monoxide and hydrogen. The developed catalysts acted as robust bifunctional electrocatalysts for cathodic ORR and anodic EOR. Specifically, the engineered HD-PdZn NCs not only displayed superior mass activity (MA, 0.461 A mg Pd -1) and specific activity (SA, 0.393 mA cm−2) at 0.9 V, which were 5.2 and 5.0 times of commercial Pt/C, respectively, but also showed enhanced stability with only 3% loss of MA after 10,000 cycles for ORR. Density functional theory (DFT) calculations revealed the Zn implantation could facilitate the reduction of OOH* to OH* on the surface of Pd during the ORR process. Moreover, HD-PdZn NCs exhibited the highest EOR mass activity with a value of 3.45 A mg Pd −1 among benchmarked catalysts in alkaline solution. The advantageous structural features and electron effects are proposed to be responsible for the remarkable bifunctional activities. This work illustrates a facile method to fabricate highly efficient bifunctional electrocatalyst for energy conversation application. [ABSTRACT FROM AUTHOR]