摘要：The electrochemical reduction of CO_(2)holds considerable promise in combating global climate change while yielding valuable chemical *** electrode assemblies operating within acidic electrolyte have exhibited noteworthy advancements in CO_(2)utilization efficiency,albeit encountering formidable competition from the hydrogen evolution *** our investigation,we introduced a silicate buffer layer,which yielded exceptional outcomes even using strong acid ***,our approach yielded a CO Faradic efficiency of 90%and reached a substantial current density of 400 mA cm^(-2).Furthermore,our system displayed remarkable stability over a 12-hour duration,and achieved a high single-pass-conversion efficiency of 67%.Leveraging in-situ Raman analysis,we attributed these performance enhancements to the augmented CO_(2)adsorption and localized alkaline environment facilitated by the incorporation of the silicate buffer *** think the addition of buffer layer to adjust the microenvironment is essential to achieve high performance and keep stable in acid condition.

摘要：Developing efficient platinum(Pt)-based electrocatalysts is enormously significant for fuel ***,we report an integrated electrocatalyst of ultralow-Pt alloy encapsulated into nitrogen-doped nanocarbon architecture for efficient oxygen reduction *** hybrid Pt-based catalyst achieves a mass activity of 3.46 A mg^(-1)_(pt)the potential of 0.9 V *** with a negligible stability decay after 10,000 *** importantly,this half-cell activity can be expressed at full cell level with a high Pt utilization of 10.22 W mg^(-1)_(Pt cathode)and remarkable durability after 30,000 cycles in *** and theoretical investigations reveal that a highly strained Pt structure with an optimal Pt-0 binding energy is induced by the incorporation of Co/Ni into Pt lattice,which would account for the improved reaction *** synergistic catalysis due to nitrogen-doped nanocarbon architecture and active Pt component is responsible for the enhanced catalytic ***,the strong metal-support interaction and optimized hydrophilic properties of nanocarbon matrix facilitate efficient mass transport and water *** work may provide significant insights in designing the low-Pt integrated electrocatalysts for fuel cells and beyond.

摘要：Gel polymer electrolytes(GPEs)has been considered as a promising candidate for the development of lithium metal batteries(LMBs)with high energy density and high safety,yet most reported GPEs is flammable,making the LMBs still facing great safety ***,we used dimethyl methylphosphate(DMMP)as the functional flame retardant and plasticizer for poly(vinylidene fluoride)(PVDF)matrix to develop a novel nonflammable PVDF-DMMP GPEs for *** DMMP not only highly enhances the flame resistance of PVDF-DMMP GPEs,the efficient dissociation of lithium salt and the rapid transport of lithium ions,but also helps to form stable and robust CEI/SEI *** a result,the ultrathin PVDF-DMMP GPEs(∼20µm)present superb flame resistance,high ionic conductivity(1.34×10^(−3) S cm^(−1) at 30℃),fast lithium ion transport(t_(Li^(+))=0.59at 30℃),high electrochemical stability voltage window(over 4 V)at 30–80℃ and uniform lithium *** used in Li∥Li symmetric cells,Li∥LiFePO_(4)(LFP)and Li∥LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) full cells,the nonflammable PVDF-DMMP GPEs could endow these cells with long-term cycle stability,high rate capability,wide-temperature operation ranges(from−20 to 80℃)and high safety *** when suffering from harsh deconstructive tests,the Li∣PVDF-DMMP GPEs∣LFP pouch cells still work normally without any safety *** actual energy density of the packed pouch cell is as high as 508 Wh kg^(−1).Therefore,our work can provide a promising strategy for the design of high safety and high-energy-density LMBs.

摘要：The design and synthesis of high‐performance and low‐cost electrocatalysts for the hydrogen evolution reaction(HER),a key half‐reaction in water electrolysis,are *** to their modest hydrogen adsorption energy,ruthenium(Ru)‐based nanomaterials are considered outstanding candidates to replace the expensive platinum(Pt)‐based HER *** this study,we developed an adsorption‐pyrolysis method to construct nitrogen(N)‐doped graphene aerogel(N‐GA)‐supported ultrafine Ru nanocrystal(Ru‐NC)nanocomposites(Ru‐NCs/N‐GA).The particle size of the Ru‐NCs and the conductivity of the N‐GA substrate can be controlled by varying the pyrolysis *** experiments reveal revealed that 10 wt%Ru‐NCs/N‐GA nanocomposites require overpotentials of only 52 and 36 mV to achieve a current density of 10 mA cm^(−2) in 1 mol/L HClO4 and 1 mol/L KOH electrolytes for HER,respectively,which is comparable to 20 wt%Pt/C *** from the ultrafine size and uniform dispersion of the Ru‐NCs,the synergy between Ru and the highly conductive substrate,and the anchoring effect of the N atom,the Ru‐NCs/N‐GA nanocomposites exhibit excellent activity and durability in the pH‐universal HER,thereby opening a new avenue for the production of commercial HER electrocatalysts.

摘要：Nano Research volume 13,pages2289–2298(2020)Cite this article 347 Accesses 1 Altmetric Metrics details Abstract Sodium-ion batteries(SIBs)are promising power sources due to the low cost and abundance of battery-grade sodium resources,while practical SIBs suffer from intrinsically sluggish diffusion kinetics and severe volume changes of electrode ***-organic framework(MOFs)derived carbonaceous metal compound offer promising applications in electrode materials due to their tailorable composition,nanostructure,chemical and physical ***,we fabricated hierarchical MOF-derived carbonaceous nickel selenides with bi-phase composition for enhanced sodium storage *** MOF formation time increases,the pyrolyzed and selenized products gradually transform from a single-phase Ni3Se4 into bi-phase NiSex then single-phase NiSe2,with concomitant morphological evolution from solid spheres into hierarchical urchin-like yolk-shell *** SIBs anodes,bi-phase NiSex@C/CNT-10h(10 h of hydrothermal synthesis time)exhibits a high specific capacity of 387.1 mAh/g at 0.1 A/g,long cycling stability of 306.3 mAh/g at a moderately high current density of 1 A/g after 2,000 *** simulation further proves the lattice mismatch at the phase boundary facilitates more interstitial space for sodium *** understanding of the phase boundary engineering of transformed MOFs and their morphological evolution is conducive to fabricate novel composites/hybrids for applications in batteries,catalysis,sensors,and environmental remediation.

摘要：Electrocatalytic nitrate reduction reaction is considered as a promising and sustainable method for ammonia ***,the selectivity and yield rate of ammonia are limited by the competitive hydrogen evolution reaction and the complex eight-electron transfer ***,we developed a(FeCoNiCu)Ox/CeO_(2)polymetallic oxide electrocatalyst for effective nitrate reduction to *** synergistic effects among the multiple elements in the electrocatalyst were clearly elucidated by comprehensive ***,Cu acted as the active site for reducing nitrate to nitrite,and Co facilitated the subsequent reduction of nitrite to ammonia,while Fe and Ni promoted water dissociation to provide ***,the incorporation of CeO_(2)increased the active surface area of(FeCoNiCu)Ox,resulting in an improved ammonia yield rate to meet industrial ***,the(FeCoNiCu)Ox/CeO_(2)electrocatalyst achieved an ammonia current density of 382 mA cm^(-2)and a high ammonia yield rate of 30.3 mg h^(-1)cm^(-2)with a long-term *** work offers valuable insights for the future design of highly efficient multi-element electrocatalysts.

摘要：Alloying and nanostructuring are two strategies used to facilitate the efficient electrocatalysis of the oxygen reduction reaction(ORR)by Pt,where the high index surfaces(HISs)of Pt exhibit superior activity for ***,we report the fabrication of PtCu3 nanodendrites possessing rich spiny branches exposing n(111)×(110)*** dendrites were formed through an etching‐modulated seeding and growing ***,an oxidative atmosphere was initially applied to form the concaved nanocubes of the Pt‐Cu seeds,which was then switched to an inert atmosphere to promote an explosive growth of ***,the oxidative or inert atmosphere failed to produce this hyperbranched *** dealloying of the PtCu3 nanodendrites produced Pt3Cu shells with Pt‐rich surfaces where HIS‐exposed dendrite structures were *** resulting PtCu_(3)@Pt_(3)Cu@Pt nanodendrites in 0.1 M HClO4 exhibited excellent mass and area specific activities for ORR,which were 14 and 24 times higher than that of commercial Pt/C,*** calculations revealed that Cu alloying and HISs both contributed to the significantly enhanced activity of Pt,and that the oxygen binding energy on the step sites of HISs on the PtCu_(3)@Pt_(3)Cu@Pt nanodendrites approached the optimal value to achieve a near peak‐top ORR activity.

摘要：将甲烷直接转化为燃料和高附加值化学品引起了越来越多的研究兴趣,然而由于甲烷的化学惰性,实现这一过程仍然是一个巨大的挑战.本文设计了12种单原子合金催化剂(SAAs)应用于甲烷的活化,利用密度泛函理论(DFT)计算和微观动力学模拟筛选出对甲烷C–H键解离具有优异催化活性的单原子合金,并在此基础上进一步研究了甲烷选择性氧化制甲醇的机理.计算结果表明,惰性金属Ag、Au和Cu基底中掺杂Ir单原子具有更高的甲烷解离活性,这主要源于甲烷C–H键与Ir原子投影d轨道之间的相互作用.在引入分子氧之后,我们提出了甲烷选择性氧化制甲醇的三种反应机理.通过DFT计算确定了3条途径的完整反应网络,同时微观动力学模拟揭示了实际反应条件下每种SAA表面上反应物种覆盖度的变化.表面覆盖度分析表明,在所有的温度范围内,Ir1/Ag表面都有利于氧化反应,而Ir1/Au和Ir1/Cu只在有限的温度区间内有利于该氧化过程,表明Ir1/Ag单原子合金是甲烷选择性氧化制甲醇反应中非常有效的单原子合金催化剂.

摘要：Lithium-sulfur(Li-S) batteries have attracted considerable attention due to their high energy density(2600 Wh kg-1). However, its commercialization is hindered seriously by the low loading and utilization rate of sulfur cathodes. Herein, we designed the cellulose-based graphene carbon composite aerogel(CCA) self-standing electrode to enhance the performance of Li-S batteries. The CCA contributes to the mass loading and utilization efficiency of sulfur, because of its unique physical structure: low density(0.018 g cm-3), large specific surface area(657.85 m2 g-1), high porosity(96%), and remarkable electrolyte adsorption(42.25 times). Compared to Al(about 49%), the CCA displayed excellent sulfur use efficiency(86%) and could reach to high area capacity of 8.60 mAh cm-2 with 9.11 mgS loading. Meanwhile,the CCA exhibits the excellent potential for pulse sensing applications due to its flexibility and superior sensitivity to electrical response signals.

摘要：The development of high‐performance nonprecious metal catalysts(NPMCs)to supersede Pt‐based catalysts for the oxygen reduction reaction(ORR)in polymer electrolyte membrane fuel cells is highly desirable but remains *** this paper,we present a pyrolysis strategy for spatial confinement and active‐site fixation using iron phthalocyanine(FePc),phthalocyanine(Pc)and Zn salts as *** the obtained carbon‐based NPMC with a hierarchically porous nanostructure of thin‐layered carbon nanosheets,nearly 100%of the total Fe species are Fe^(Ⅱ)‐N_(4) active *** contrast,pyrolyzing FePc alone forms Fe‐based nanoparticles embedded in amorphous carbon with only 5.9%Fe^(Ⅱ)‐N_(4) active *** experimental characterization and density functional theory calculations reveal that spatial confinement through the staggeredπ–πstacking of Pc macrocycles effectively prevents the demetallation of Fe atoms and the formation of Fe‐based nanoparticles via ***,Zn‐induced microporous defects allow the fixation of Fe^(Ⅱ)‐N_(4) active *** synergistic effect of staggered stacking confinement and microporous defect fixation results in a high density of atomic Fe^(Ⅱ)‐N_(4) active sites that can enhance the *** optimal Fe^(Ⅱ)‐N_(4)‐C electro‐catalyst outperforms a commercial Pt/C catalyst in terms of half‐wave potential,methanol toler‐ance,and long‐term stability in alkaline *** modulation strategy can greatly advance efforts to develop high‐performance NPMCs.