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A palladium phosphide electrocatalyst supported on carbon black (PdP2@CB) shows efficient water splitting in both alkaline and neutral electrolytes. Significantly lower overpotentials are required for PdP2@CB (27.5 mV in 0.5 m H2SO4; 35.4 mV in 1 m KOH; 84.6 mV in 1 m PBS) to achieve a HER electrocatalytic current density of 10 mA cm−2 compared to commercial Pt/CB (30.1 mV in 0.5 m H2SO4; 46.6 mV in 1 m KOH; 122.7 mV in 1 m PBS). Moreover, no loss in HER activity is detectable after 5000 potential sweeps. Only 270 mV and 277 mV overpotentials are required to reach a current density of 10 mA cm−2 for PdP2@CB to catalyze OER in 1 m KOH and 1 m PBS electrolytes, which is better OER activity than the benchmark IrO2 electrocatalyst (301 mV and 313 mV to drive a current density of 10 mA cm−2). 1.59 V and 1.72 V are needed for PdP2@CB to achieve stable water splitting catalytic current density of 10 mA cm−2 in 1 m PBS and 50 mA cm−2 in 1 m KOH for 10 h, respectively.

Two-dimensional Mo/Mo 2 C heteronanosheets (Mo/ Mo 2 C-HNS) were successfully prepared via a NaCl template-assisted synthesis route followed by a controllable simultaneous reduction and carbonization of MoO 3 nanosheets for efficient hydrogen evolution reaction (HER) catalysis under both acidic and alkaline conditions. The Mo species in the atomically thin Mo/Mo 2 C-HNS not only guarantees the rapid transport of electrons but also optimizes the electronic configuration of β-Mo 2 C. Besides, the abundant Mo/β-Mo 2 C heterointerfaces in nanodimension afford large numbers of additional heterogeneous catalytic sites. HER electrocatalytic performance with overpotential of merely 89 mV to drive a current density of 10 mA/cm 2 in 0.5 M H 2 SO 4 is therefore achieved. Strikingly, stable chronoamperometric electrolysis for 20 h and also an impressive cycling stability with negligible overpotential decay over 4000 sweeps demonstrate its considerable durability in an acidic environment. These findings highlight the promising potential of Mo/Mo 2 C-HNS catalyst as an efficient and stable noble metal-free electrocatalyst toward the HER.

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electrode kinetics, large volume change, and physical strains during the Li insertion/ extraction process, resulting in large polarization, rapidly declining capacity, and poor rate performances. [10] Moreover, it had been detected by various in situ techniques that serious irreversible transformation from crystallization to amorphous phase would occur for conversion type anodes along with their first discharge-charge process, which tends to lead poor initial coulombic efficiency (ICE) and fast capacity decay. [11] To better relax the structure stress during the charging/discharging, efforts have been made to synthesize the isotropic amorphous nanomaterials from the beginning to facilitate the stress relaxation and fruitful percolation pathway, which are proved effective to promote their cycle performance. [12] However, the low initial coulomb efficiency (usually <70%) and large voltage polarization are still unsolved due to the low conductivity of the electrode and poor electrochemical reversibility of the discharge product Li 2 O, which seriously impede the commercialization of such metal oxides anode materials. [13] Compared with the metal oxides, the typical layer structured metal sulfides or selenides MX 2 (M = Mo, W, X = S, Se) have attracted more and more research attention in recent years due to their unique structure properties and much better conductivity. [14] On the one hand, these metal sulfides possess superior structure flexibility due to their unique layered structure, which enables capabilities of quick Li ion intercalation, fast ion diffusion, and swift charge transfer along the interlayer space. [15] On the other hand, the conductivity of these sulfide or selenides (≈ ≥10 −4 S cm −1 ) is much higher than that of the metal oxides (≈ ≤10 −6 S cm −1 ) as well. [16] Moreover, metal sulfides show lower voltage as well as smaller charge/discharge voltage polarization than that of the metal oxides, promising a larger energy density and higher energy efficiency when assembled into the full cells. [17] However, similar to metal oxides, metal sulfide or selenides still suffer from serious structure destruction of their ordered layer characteristic, and the broken MX bonding along with lithiation process is hard to be rebuilt again even after Li + extraction. [10b,18] As a result, the electrode was mainly composed of metal M and S (Se) instead of original MX 2 after the first cycle, as reported in the typical cases of WS 2 and MoS 2 materials. [19] Therefore, low initial coulomb efficiency and The metal sulfide or selenides have attracted increasing attention for highenergy lithium-ion batteries due to their unique layer structure flexibility, higher conductivity, and lower voltage polarization than metal oxides. However, low initial coulomb efficiency (ICE), serious structure destruction, and irreversible bonding chemistry are still big challenges for their practical application. Herein, layer GeSe 2 and its carbon composite are synthesized by high-energy ball milling and it is surprisingly found that ...

Selective cleavage of C-C bonds is very important in organic chemistry, but remains challenging because of their inert chemical nature. Herein, we report that Zn/NC-X catalysts, in which Zn2+ coordinate with N species on microporous N-doped carbon (NC) and X denotes the pyrolysis temperature, can effectively catalyze aerobic oxidative cleavage of C(CO)-C bonds and quantitatively convert acetophenone to methyl benzoate with a yield of 99% at 100 °C. The Zn/NC-950 can be applied for a wide scope of acetophenone derivatives as well as more challenging alkyl ketones. Detail mechanistic investigations reveal that the catalytic performance of Zn/NC-950 can be attributed to the coordination between Zn2+ and N species to change the electronic state of the metal, synergetic effect of the Zn single sites with their surrounding N atoms, as well as the microporous structure with the high surface area and structural defects of the NC.

Herein, we report a series of CuPd catalysts for electrochemical hydrogenation (ECH) of furfural to 2‐methylfuran (MF or FurCH3 where Fur=furyl) in aqueous 0.1 M acetic acid (pH 2.9). The highest faradaic efficiency (FE) for MF reached 75 % at −0.58 V vs. reversible hydrogen electrode with an average partial current density of 4.5 mA cm−2. In situ surface‐enhanced Raman spectroscopic and kinetic isotopic experiments suggested that electrogenerated adsorbed hydrogen (Hads) was involved in the reaction and incorporation of Pd enhanced the surface coverage of Hads and optimized the adsorption pattern of furfural, leading to a higher FE for MF. Density functional theory calculations revealed that Pd incorporation reduced the energy barrier for the hydrogenation of FurCH2* to FurCH3*. Our study demonstrates that catalyst surface structure/composition plays a crucial role in determining the selectivity in ECH and provides a new strategy for designing advanced catalysts for ECH of bio‐derived oxygenates.