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Transition‐metal atomic site catalysts (ASCs) are a new class of catalytic system for CO2 electroreduction, however, their practical application is greatly hindered by the challenge that it's still difficult for them to simultaneously achieve industrial‐level current density and high selectivity. Herein a new strategy is reported for hundreds of gram‐scale and low‐cost production of Ni‐ASCs on 3D porous nanocarbon with high‐loading NiN3 sites for greatly boosting the electroreduction of CO2 to CO with both industrial‐level current density and high selectivity. It is discovered that although Ni‐ASCs with high‐loading (Ni‐ASCs/4.3 wt.%) and low‐loading (Ni‐ASCs/0.8 wt.%) both show above 95% Faradic efficiency for CO (FECO) under a wide potential range in H‐cell, in flow cell, Ni‐ASCs/0.8 wt.% can only achieve FECO of 43.6% at a current density of 343.9 mA cm−2, significantly lower than those (95.1%, 533.3 mA cm−2) of Ni‐ASCs/4.3 wt.% under same potential, first revealing the important role of high‐loadings of single atom sites in promoting the high‐selectivity electrolysis at industrial‐level current density. Most importantly, it is demonstrated that Ni‐ASCs/4.3 wt.%‐based membrane electrode assembly (MEA) exhibits outstanding durability at industrial‐level current density of 360.0 mA cm−2, which is one of the best performances for the realistic electroreduction of CO2 to CO in the reported ASCs‐based MEA systems. [ABSTRACT FROM AUTHOR]

The hydrogen evolution reaction (HER) is a pivotal element of electrochemical water splitting which is able to produce clean hydrogen as an alternative to fossil fuel. Developing efficient Pt‐based electrocatalysts for the HER to work at all pHs is highly desirable, however, still a significant challenge, especially in alkaline conditions due to sluggish water dissociation and OHad transfer. Here, a new strategy for making a class of amorphous WOx‐surface decorated PtNi@Pt dendritic nanowires (WOx‐PtNi@Pt DNWs) to achieve highly efficient pH‐universal HER electrocatalysis is reported. The as‐made WOx‐PtNi@Pt DNWs display superior HER performance with the overpotentials of 24, 5, and 22 mV in 0.1 m KOH, 0.1 m HClO4, and 0.5 m phosphate‐buffered saline, respectively, at a current density of 10 mA cm−2. The mass activity of WOx‐PtNi@Pt DNWs in alkaline conditions is 3.3 mA μgPt−1 at an overpotential of 70 mV, among the best in all the reported materials. Theoretical calculations confirm the introduction of WOx to the PtNi DNWs plays a pivotal role in promoting the efficient electron transfer for the alkaline and acidic HER. The activation of the PtNi region within the PtNiWO interface is achieved by the WOx induced strain effect, which guarantees the superior performance in the HER. [ABSTRACT FROM AUTHOR]

Abstract: Searching for highly efficient and durable electrocatalysts for the hydrogen evolution reaction (HER) that function effectively at all pHs is of great interest to the scientific community, however it is still a grand challenge, because the HER kinetics of Pt in alkaline solutions are approximately two to three orders of magnitude lower than that in acidic solution. Herein, a new class of wrinkled, ultrathin Rh2P nanosheets for enhancing HER catalysis at all pHs is reported. They exhibit a small overpotential of 18.3 mV at 10 mA cm−2, low Tafel slope of 61.5 mV dec−1, and good durability in alkaline media, much better than the commercial Pt/C catalyst. Density functional theory calculations reveal that the active open‐shell effect from the P‐3p band not only promotes Rh‐4d for increased proton–electron charge exchange but also provides excellent p–p overlapping to locate the O‐related species as distributary center, which can benefit the HER process in alkaline media. It is also demonstrated that the present wrinkled, ultrathin Rh2P nanosheets are highly efficient and durable electrocatalysts toward HER in both acid and neutral electrolytes. The present work opens a new material design for ultrathin 2D metal phosphide nanostructures for the purpose of boosting HER performance at all pHs. [ABSTRACT FROM AUTHOR]

Abstract: The development of high‐performance oxygen reduction reaction (ORR) catalysts derived from non‐Pt group metals (non‐PGMs) is urgent for the wide applications of proton exchange membrane fuel cells (PEMFCs). In this work, a facile and cost‐efficient supramolecular route is developed for making non‐PGM ORR catalyst with atomically dispersed Fe‐Nx/C sites through pyrolyzing the metal‐organic polymer coordinative hydrogel formed between Fe3+ and α‐L‐guluronate blocks of sodium alginate (SA). High‐angle annular dark field scanning transmission electron microscopy (HAADF‐STEM) and X‐ray absorption spectroscopy (XAS) verify that Fe atoms achieve atomic‐level dispersion on the obtained SA‐Fe‐N nanosheets and a possible fourfold coordination with N atoms. The best‐performing SA‐Fe‐N catalyst exhibits excellent ORR activity with half‐wave potential (E1/2) of 0.812 and 0.910 V versus the reversible hydrogen electrode (RHE) in 0.5 m H2SO4 and 0.1 m KOH, respectively, along with respectable durability. Such performance surpasses that of most reported non‐PGM ORR catalysts. Density functional theory calculations suggest that the relieved passivation effect of OH* on Fe‐N4/C structure leads to its superior ORR activity to Pt/C in alkaline solution. The work demonstrates a novel strategy for developing high‐performance non‐PGM ORR electrocatalysts with atomically dispersed and stable M‐Nx coordination sites in both acidic and alkaline media. [ABSTRACT FROM AUTHOR]

Abstract: The adequate potassium resource on the earth has driven the researchers to explore new‐concept potassium‐ion batteries (KIBs) with high energy density. Graphite is a common anode for KIBs; however, the main challenge faced by KIBs is that K ions have the larger size than Li and Na ions, hindering the intercalation of K ions into electrodes and thus leading to poor rate performance, low capacity, and cycle stability during the potassiation and depotassiation process. Herein, an amorphous ordered mesoporous carbon (OMC) is reported as a new anode material for high‐performance KIBs. Unlike the well‐crystallized graphite, in which the K ions are squeezed into the restricted interlayer spacing, it is found that the amorphous OMC possesses larger interlayer spacing in short range and fewer carbon atoms in one carbon‐layers cluster, making it more flexible to the deformation of carbon layers. The larger interlayer spacing and the unique layered structure in short range can intercalate more K ions into the carbon layer, accommodate the increase of the interlayer spacing, and tolerate the volume expansion, resulting in a battery behavior with high capacity, high rate capability, and long cycle life. [ABSTRACT FROM AUTHOR]

Ordered intermetallic alloys have attracted extensive attention as advanced electrocatalysts for polymer electrolyte membrane fuel cells (PEMFCs) reactions with much improved activity and stability. Here, latest progress in tuning intermetallic Pt- and Pd-based nanocrystals with tunable morphology and structure for catalyzing both the cathodic reduction of oxygen and anodic oxidation of fuels (e.g., methanol, ethanol and formic acid) in PEMFCs is highlighted. Making/tuning interesting intermetallic PtM (M = Fe, Co, Pb, Cu, etc.)-based nanocrystals for boosting oxygen reduction reaction with high activity and stability by using/controlling high-temperature annealing treatment is discussed. In all the reported Pt-based intermetallic nanocrystals, controlling the degree of ordering under the proper high temperature treatment is the key for achieving the optimized electrocatalysis. In order to search for cheaper catalysts, the progress on making Pd-based intermetallic nanocrystals is also discussed. Furthermore, future research directions are proposed and discussed to further enhance the efficiency of such unique intermetallic multimetallic nanocatalysts. This report aims to demonstrate the potential of ordered intermetallic strategy for boosting electrocatalysis and stimulating more research efforts in this field. [ABSTRACT FROM AUTHOR]

LiFePO4/carbon hybrid microtubes (LFP/CMT) are synthesized through the use of the strong chelation interaction with Fe3+ and absorb interaction with Li+ of alginate. This approach yields LFP/CMT with the lowest Fe–Li antisite defects, which exhibits remarkable capacity, rate ability, and long‐term cycling stability for Li ion batteries. [ABSTRACT FROM AUTHOR]

A TiO2 nanotube photoanode is introduced into H2O2‐based fuel cells to improve their performance by utilizing light energy and biomass power. Upon UV illumination, the light‐driven, membraneless, H2O2‐based fuel cells exhibit a high open‐circuit potential (OCP) of 0.595 V and stable power density of 90 μW cm–2. [ABSTRACT FROM AUTHOR]

Freestanding composite structures with embedded transition metal dichalcogenides (TMDCs) as the active material are highly attractive in the development of advanced electrodes for energy storage devices. Most 3D electrodes consist of a bilayer design involving a core–shell combination. To further enhance the gravimetric and areal capacities, a 3D trilayer design is proposed that has MoSe2 as the TMDC sandwiched in‐between an inner carbon nanotube (CNT) core and an outer carbon layer to form a CNT/MoSe2/C framework. The CNT core creates interconnected pathways for the e−/Na+ conduction, while the conductive inert carbon layer not only protects the corrosive environment between the electrolyte and MoSe2 but also is fully tunable for an optimized Na+ storage. This unique heterostructure is synthesized via a solvothermal‐carbonization approach. Due to annealing under a confined structural configuration, MoSe2 interlayer spaces are expanded to facilitate a faster Na+ diffusion. It is shown that an ≈3 nm thick carbon layer yielded an optimized anode for a sodium‐ion battery. The 3D porosity of the heterostructure remains intact after an intense densification process to produce a high areal capacity of 4.0 mAh cm−2 and a high mass loading of 13.9 mg cm−2 with a gravimetric capacity of 347 mAh g−1 at 500 mA g−1 after 500 cycles. [ABSTRACT FROM AUTHOR]

Subzero‐temperature Li‐ion batteries (LIBs) are highly important for specific energy storage applications. Although the nickel‐rich layered lithium transition metal oxides(LiNixCoyMnzO2) (LNCM) (x > 0.5, x + y +z = 1) are promising cathode materials for LIBs, their very slow Li‐ion diffusion is a main hurdle on the way to achieve high‐performance subzero‐temperature LIBs. Here, a class of low‐temperature organic/inorganic hybrid cathode materials for LIBs, prepared by grafting a conducting polymer coating on the surface of 3 µm sized LiNi0.6Co0.2Mn0.2O2 (LNCM‐3) material particles via a greener diazonium soft‐chemistry method is reported. Specifically, LNCM‐3 particles are uniformly coated with a thin polyphenylene film via the spontaneous reaction between LNCM‐3 and C6H5N2+BF4−. Compared with the uncoated one, the polyphenylene‐coated LNCM‐3 (polyphenylene/LNCM‐3) has shown much improved low‐temperature discharge capacity (≈148 mAh g−1 at 0.1 C, −20 °C), outstanding rate capability (≈105 mAh g−1 at 1 C, −20 °C), and superior low‐temperature long‐term cycling stability (capacity retention is up to 90% at 0.5 C over 1150 cycles). The low‐temperature performance of polyphenylene/LNCM‐3 is the best among the reported state‐of‐the art cathode materials for LIBs. The present strategy opens up a new avenue to construct advanced cathode materials for wider range applications. A class of low‐temperature organic/inorganic hybrid cathode materials for Li‐ion batteries is prepared by grafting a conducting polymer coating on the surface of 3 µm sized LiNi0.6Co0.2Mn0.2O2 (LNCM‐3) material particles via a greener diazonium soft‐chemistry method. The polyphenylene‐coated LNCM‐3 (polyphenylene/LNCM‐3) has shown much improved low‐temperature electrochemical performance. [ABSTRACT FROM AUTHOR]