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We report the overall structure and trifunctionality catalytic application of an atomically precise alloy nanocluster of Ag20Rh2(C≡C‐tBu)16(CF3CO2)6(H2O)2 (abbreviated as Ag20Rh2 hereafter). Ag20Rh2 has a twisted rod‐like structure, where a Ag4@Rh2 kernel is connected by two twisted Ag8 cubes on two sides. Ag20Rh2 is a superatomic cluster with four free valence electrons, and it has characteristic absorbance feature. Interestingly, Ag20Rh2 exhibited superior catalytic performance than the larger AgRh nanoparticle counterparts in electrochemical hydrogen evolution reaction (HER), reduction of 4‐nitrophenol, and the methyl orange degradation reaction. Such intriguing catalytic properties are attributed to the more exposed active sites from the ultrasmall nanoclusters than relatively large nanoparticles. This study not only enriches the family member of alkynyl‐protected AgRh nanoclusters with atomic precision, but also highlights the great advantages of employing nanoclusters as efficient catalysts for multiple functionalities. [ABSTRACT FROM AUTHOR]

We report two atomically precise alloy nanoclusters of Ag4Rh2(C≡CArF)8(PPh3)2 and Au4Rh2(C≡CArF)8(PPh3)2 (Ar = 3,5-(CF3)2C6H3, abbreviated as Ag4Rh2 and Au4Rh2, respectively) co-protected by alkynyl and phosphine ligands. Both clusters have identical octahedral metal core configurations and can be termed superatoms with two free electrons. However, they possess different optical features, manifested by totally different absorbance peaks, and drastically different emission peaks, and also, Ag4Rh2 has a much higher fluorescence quantum yield (18.43%) than Au4Rh2 (4.98%). Moreover, Au4Rh2 exhibited markedly superior catalytic performance in the electrochemical hydrogen evolution reaction (HER), manifested by a much lower overpotential at 10 mA cm−2 and better stability. Density functional theory (DFT) calculations revealed that the free energy change of Au4Rh2 for the adsorption of two H* (0.64 eV) is lower than that of Ag4Rh2 for the adsorption of one H* (−0.90 eV) after stripping a single alkynyl ligand from the cluster. In contrast, Ag4Rh2 demonstrated much stronger catalytic capability for catalyzing 4-nitrophenol reduction. The present study provides an exquisite example to understand the structure–property relationship of atomically precise alloy nanoclusters, and emphasizes the importance of fine-tuning of the physicochemical properties and catalytic performance of the metal nanoclusters through modulating the metal core and beyond. [ABSTRACT FROM AUTHOR]

We report the structure analysis, optical property, and catalytic implications of homoleptic alkynyl‐protected Au(I)‐Ag(I) nanocluster, namely Au9Ag9(C≡CArF)18 (abbreviated as Au9 Ag9 hereafter). Single crystal X‐ray diffraction analysis disclosed that, the core of Au9Ag9 cluster features intriguing ichthyomorphic assembled structure driven by metallophilic interactions and Au‐acetylide linkages. The Au9Ag9 nanocluster is fluorescent in both solution and solid state, and it has much higher quantum yield in solid state. In the electrochemical hydrogen evolution reaction (HER) test, Au9Ag9 nanocluster exhibits a favorable overpotential of 274 mV at 10 mA cm−2 with a Tafel slope of 99 mV dec−1, which markedly surpass than the [Au(C≡C‐ArF)]f and [Ag(C≡C‐ArF)]f control samples. Furthermore, Au9Ag9 nanocluster shows much higher activity than the other two to catalyze the reduction of 4‐nitrophenol. [ABSTRACT FROM AUTHOR]

A facile two-step method is developed for large-scale synthesis of chemically ordered Pt3Co nanoparticles (NPs) as a high-performance catalyst for hydrogen evolution reaction. Due to the NaCl-matrix as dispersing media avoids the severe aggregation during the high-temperature annealing process, the resulting Pt3Co NPs are pure and well crystallized with narrow size distribution. Furthermore, the chemically ordered Pt3Co NPs exhibit excellent HER property in acidic solution. Our methodology can be also applied to synthesis of other Pt-based NPs. [ABSTRACT FROM AUTHOR]

We report the structure analysis and electrocatalytic application toward overall water splitting of atomically precise Au 15 Ag 23 ( t BuC ≡ C) 18 Br 6 nanoclusters (Au 15 Ag 23 in short). Au 15 Ag 23 possesses a triple-layered core-shell-shell metal core structure of Au 6 @Au 6 Ag 23 @Au 3 , with the core centre being a tetragonal bipyramidal Au 6 structure unit, and the outer layer of one Ag atom linked with two alkynyl ligands to form a linear structural motif covering the surface of the metal nucleus. Au 15 Ag 23 is a superatom with 14 free electrons and it displays a unique absorption profile. Remarkably, the Au 15 Ag 23 catalyst exhibits excellent electrocatalytic properties in hydrogen evolution reaction (HER), manifested by a low overpotential of 125 mV at 10 mA cm−2 and a negligible current decrease for 16 h in 0.5 M H 2 SO 4 , while the Au 15 Ag 23 /NiFe-LDH catalyst demonstrates outstanding electrocatalytic performance in oxygen evolution reaction (OER), evidenced by an ultralow overpotential of 250 mV at 10 mA cm−2 and a ∼5% current decrease for 30 h in 1.0 M KOH. Such promoting effect is ascribed by the electron transfer from NiFe-LDH to the Au 15 Ag 23 clusters, which results in generating high valent Fe species as active sites. When using the two catalysts for overall water splitting (OWS), only 1.51 V was required to achieve a current density of 10 mA cm−2, and it performed well in the 50 h's stability test. This study enriches the family member of alkynyl-protected AuAg bimetallic nanoclusters, and further highlights the dual functionalities (catalyzing HER and promoting OER) that metal nanoclusters can make contribution for electrochemical energy conversion and beyond. [Display omitted] • A novel atomically precise Au 15 Ag 23 ( t BuC ≡ C) 18 Br 6 nanocluster is reported. • Au 15 Ag 23 cluster possess intriguing HER catalytic properties. • Au 15 Ag 23 cluster can significantly promote the OER performance of NiFe-LDH. • The electron transfer from NiFe-LDH to Au 15 Ag 23 cluster boosted the OER performance. [ABSTRACT FROM AUTHOR]

The activity of iron oxyhydroxides (FeOOH) in oxygen evolution reaction (OER) is limited by their poor conductivity and the high energy barrier in the rate-determining step. Herein, we report the immobilization of atomic dispersed Pd species on Co doped FeOOH, realizing the preparation of amorphous hetero-structure FeCo a OOH-Pd b. In the case of Co/Fe of 0.68 and Pd/Fe of 0.026, the coexisting structure of nanorods and nanospheres with appropriate oxygen vacancies and unsaturated active centers increases the number of active sites and enhances the intrinsic activity of the electrocatalyst. The density functional theory results uncover that the FeCo 0.68 OOH-Pd 0.026 optimizes the binding energies of *O and *OOH, and accelerates the OER kinetics. The rationally designed FeCo 0.68 OOH-Pd 0.026 exhibits excellent OER activity and reliability, manifesting a Tafel slope of 37.5 mV dec−1, a low overpotential of 265.1 mV at 10 mA cm−2, which has the potential to realize the large-scale implementation of water splitting. [Display omitted] • Outstanding OER activity over hetero-structure FeCo 0.68 OOH-Pd 0.026. • Co doping controls the formation of hetero-structure and oxygen vacancies. • Atomic dispersed Pd species form unsaturated coordination centers on the surface of amorphous supports. • Rationally designed FeCo 0.68 OOH-Pd 0.026 overcomes the poor conductivity and the sluggish kinetics between *O and *OOH of FeOOH. [ABSTRACT FROM AUTHOR]