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Transferring urea-containing waste water to clean hydrogen energy has received increasing attention, while challenges are still faced in the sluggish catalytic kinetics of urea oxidation. Herein, a novel hybrid catalyst of Ni2P/Ni3N embedded in nitrogen-doped carbon nanofiber (Ni2P/Ni3N/NCNF) is developed for energy-relevant urea-containing water-splitting reactions. The built-in electrophilic/nucleophilic domain resulting from the electron transfer from Ni2P to Ni3N accelerates the formation of high-valent active Ni species and promotes favourable urea molecule adsorption. A spectral study and theoretical analysis reveal that the negatively shifted Ni d-band centre in Ni2P/Ni3N/NCNF weakens the adsorption of intermediate CO2 and facilitates its desorption, thereby improving the urea oxidation reaction kinetics. The overall reaction process is also optimized by minimizing the energy barrier of the rate-determining step. Following the stability test, the surface reconstruction of the pre-catalyst is discussed, where an amorphous layer of NiOOH as the real active phase is formed on the surface/interface of Ni2P/Ni3N for urea oxidation. Benefiting from these characteristics, a high current density of 151.11 mA cm-2 at 1.54 V vs. RHE is obtained for urea oxidation catalysed by Ni2P/Ni3N/NCNF, exceeding that of most of the similar catalysts. A low cell voltage of 1.39 V is required to reach 10 mA cm-2 for urea electrolysis, which is about 200 mV less than that of the general water electrolysis. The current work will be helpful for the development of advanced catalysts and their application in the urea-containing waste water transfer to clean hydrogen energy.
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Urea electrosynthesis has appeared to meet the nitrogen cycle and carbon neutrality with energy-saving features. Copper can co-electrocatalyze among CO2 and nitrogen species to generate urea, however developing effective electrocatalysts is still an obstacle. Here, we developed a nitrogen-doped porous carbon loaded with FeCu clusters that convert CO2 and NO3- into urea, with the highest Faradaic efficiency of 39.8 % and yield rate of 1024.6 µg h-1 mgcat.-1, under optimized ambient conditions, exceeding that at the Fe or Cu homogeneous sites. Furthermore, a favorable CN coupling pathway originates from *NHCO and *NHCONO two intermediates with lower free energy barriers on FeCu dual active sites are verified through in-situ Fourier transform infrared spectroscopy and theoretical calculations. This research might provide deep insights into coupling mechanisms and investigation of efficient catalysts for green urea production.
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Artroplastia de Reemplazo de Cadera , Prótesis de Cadera , Diseño de Prótesis , Reoperación , Humanos , Artroplastia de Reemplazo de Cadera/métodos , Artroplastia de Reemplazo de Cadera/instrumentación , Artroplastia de Reemplazo de Cadera/efectos adversos , Reoperación/métodos , Falla de PrótesisRESUMEN
Ethylene glycol electrooxidation catalyzed by Pd nanoparticles was found to be largely improved by Bi2Te3 nanosheets both in the dark and under visible light irradiation.
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MoP nanofiber-coupled Pd nanoparticles were demonstrated as efficient catalysts for formic acid-assisted water splitting in hydrogen generation. The theoretical calculations indicated that the OH on the surface of MoP through d-p bonding promoted the oxidation of CO at the Pd sites, and improved the ability to resist CO poisoning. As a result, enhanced catalytic performance was indicated.
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Strengthening the hydroxyl binding energy (OHBE) on Ru surfaces for efficient hydrogen oxidation reaction (HOR) in alkaline electrolytes at the expense of narrowing the effective potential window (EPW) increases the risk of passivation under transient conditions for the alkaline exchange membrane fuel cell technique. Herein, an effective Ru/NiSe2 catalyst was reported which exhibits a gradually enhanced intrinsic activity and slightly enlarged EPW with the increased degree of coupling between Ru and NiSe2. This promotion could be attributed to the optimized electron distribution and d-band structures of Ru surfaces weakening the hydrogen binding energy and especially the OHBE through the strong d-p orbital hybridization between Ru and NiSe2. Unlike the conventional way of strengthened OHBE enhancing the oxidative desorption of hydrogen intermediates (Had) via the bi-functional mechanism, the weakened OHBE on this Ru/NiSe2 model catalyst alleviates the competitive adsorption between Had and the hydroxyl intermediates (OHad), thereby accelerating the HOR kinetics at low overpotentials and hindering the full poisoning of the catalytic surfaces by strongly adsorbed OHad spectators at high overpotentials. The work reveals a missed but important approach for Ru-based catalyst development for the fuel cell technique.
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A novel Ni(OH)2/MnCO3 hybrid catalyst was developed for high-performing alkaline methanol electro-oxidation, which could well overcome the shortages of inactive MnCO3 and low intrinsic Ni(OH)2 due to the good synergistic catalysis effect from the Jahn-Teller distortion effect.
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Tracking the trajectory of hydrogen intermediates during hydrogen electro-catalysis is beneficial for designing synergetic multi-component catalysts with division of chemical labor. Herein, we demonstrate a novel dynamic lattice hydrogen (LH) migration mechanism that leads to two orders of magnitude increase in the alkaline hydrogen oxidation reaction (HOR) activity on Pd@Pt over pure Pd, even ≈31.8â times mass activity enhancement than commercial Pt. Specifically, the polarization-driven electrochemical hydrogenation process from Pd@Pt to PdHx @Pt by incorporating LH allows more surface vacancy Pt sites to increase the surface H coverage. The inverse dehydrogenation process makes PdHx as an H reservoir, providing LH migrates to the surface of Pt and participates in the HOR. Meanwhile, the formation of PdHx induces electronic effect, lowering the energy barrier of rate-determining Volmer step, thus resulting in the HOR kinetics on Pd@Pt being proportional to the LH concentration in the in situ formed PdHx @Pt. Moreover, this dynamic catalysis mechanism would open up the catalysts scope for hydrogen electro-catalysis.
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A facile strategy is developed to fabricate 3 nm RuIrOx nanocrystals anchored onto N-doped hollow carbon for highly efficient and pH-universal overall water splitting and alkaline seawater electrolysis. The designed catalyst exhibits much lower overpotential and superior stability than most previously reported Ru- and Ir-based electrocatalysts for hydrogen/oxygen evolution reactions. It also manifests excellent overall water splitting activities and maintains ≈100% Faradic efficiency with a cell voltage of 1.53, 1.51, and 1.54 V at 10 mA cm-2 for 140, 255, and 200 h in acid, alkaline, and alkaline seawater electrolytes, respectively. The excellent electrocatalytic performance can be attributed to solid bonding between RuIrOx and the hollow carbon skeleton, and effective electronic coupling between Ru and Ir, thus inducing its remarkable electrocatalytic activities and long-lasting stability.
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MAX phase combines both ceramic and metallic properties, which exhibits widespread application prospects. 2D MAX nanosheets have more abundant surface-active sites, being anticipated to improve the performance of surface-related applications. Herein, for the first time, 2D Nb2AlC nanosheets (NSs) as novel supports anchored with Ru catalysts for overall water splitting are developed. The optimized catalyst of Ru@Nb2AlC NSs exhibit Pt-comparable kinetics and superior catalytic activity toward hydrogen evolution reaction (HER) (low overpotentials of 61 and 169 mV at 10 and 100 mA cm-2, respectively) with excellent durability (5000 cycles or 80 h) in alkaline media. In particular, Ru@Nb2AlC NSs achieve a mass activity of ≈4.8 times larger than the commercial Pt/C (20 wt.%) catalyst. The post-oxidation resultant catalyst of RuO2@Nb2AlC NSs also exhibit boosting HER and oxygen evolution reaction activities and ≈100% Faraday efficiency for overall water splitting with a cell voltage of 1.61 V to achieve 10 mA cm-2. Therefore, the novel category of 2D MAX supports anchored with Ru nanocrystals offers a novel strategy for designing a wide range of MAX-supported metal catalysts for the renewable energy field.
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Zn-NO3- batteries can generate electricity while producing NH3 in an environmentally friendly manner, making them a very promising device. However, the conversion of NO3- to NH3 involves a proton-assisted 8-electron (8e-) transfer process with a high kinetic barrier, requiring high-performance catalysts to realize the potential applications of this technology. Herein, we propose a heterostructured CoO/CuO nanoarray electrocatalyst prepared on a copper foam (CoO/CuO-NA/CF) that can electrocatalytically and efficiently convert NO3- to NH3 at low potential and achieves a maximum NH3 yield of 296.9 µmol h-1 cm-2 and the Faraday efficiency (FE) of 92.9% at the -0.2 V vs. reversible hydrogen electrode (RHE). Impressively, Zn-NO3- battery based on the monolithic CoO/CuO-NA/CF electrode delivers a high NH3 yield of 60.3 µmol h-1 cm-2, FENH3 of 82.0%, and a power density of 4.3 mW cm-2. This study provides a paradigm for heterostructured catalyst preparation for the energy-efficient production of NH3 and simultaneously generating electrical energy.
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Fe-doping effect-induced heterostructure formation and charge redistribution in Fe-doped NiS were revealed significantly for boosting the electrochemical oxygen evolution reaction.
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Introduction: Collegiate student-athletes often encounter various stressors stemming from academic study and athletic training, which can potentially have negative effects on their well-being. This study investigates how collegiate student-athletes' openness to experience and their engagement in knowledge sharing influence their well-being, as well as the moderating role of perceived coaching effectiveness. Methods: To examine these relationships, we propose and test a conceptual framework using an online survey conducted among collegiate student-athletes from a southeastern province of China. The participants consisted of 484 collegiate student-athletes who voluntarily participated in the study. We used regression analysis and mediation analysis to test the proposed relationships among the variables. Results: Openness to experience has a positive impact on knowledge sharing (ß = 0.552, p < 0.05); knowledge sharing with peers positively affects collegiate student-athlete well-being (ß = 0.415, p < 0.05) and mediates the relationship between openness to experience and collegiate student-athlete well-being (ß = 0.086, p < 0.05). Perceived coaching effectiveness positively moderates the relationship between openness to experience and knowledge sharing (ß = 0.170, p < 0.05). Discussion: Our study contributes to the collegiate student-athlete literature by shedding light on the factors that influence their well-being, with insights that bear important managerial implications for universities and coaches.
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The development of efficient and affordable electrode materials is crucial for clean energy storage systems, which are considered a promising strategy for addressing energy crises and environmental issues. Metal phosphorous chalcogenides (MPX3 ) are a fascinating class of two-dimensional materials with a tunable layered structure and high ion conductivity, making them particularly attractive for energy storage applications. This review article aims to comprehensively summarize the latest research progress on MPX3 materials, with a focus on their preparation methods and modulation strategies. Additionally, the diverse applications of these novel materials in alkali metal ion batteries, metal-air batteries, and all-solid-state batteries are highlighted. Finally, the challenges and opportunities of MPX3 materials are presented to inspire their better potential in energy storage applications. This review provides valuable insights into the promising future of MPX3 materials in clean energy storage systems.
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It is an appealing avenue for electrosyntheis of high-valued chemicals at both anode and cathode by coupling 5-hydroxymethylfurfural (HMF) oxidation and nitrate reduction reactions simultaneously, while the development such bifunctional electrocatalysts is still in its infancy with dissatisfied selectivity and low yield rate. Here, we first report that Zn-doped Co3O4 nanowires array can be served as an efficient and robust dual-functional catalyst for HMF oxidation and nitrate reduction at ambient conditions. Specifically, the catalyst shows a faradaic efficiency of 91 % and a yield rate of 241.2 µmol h-1 cm-2 for 2,5-furandicarboxylic acid formation together with a high conversion of nearly 100 % at a potential of 1.40 V. It also displays good cycling stability. Besides, the catalyst is capable of catalyzing the reduction of nitrate to NH3, giving a maximal faradaic efficiency of 92 % and a peak NH3 yield rate of 4.65 mg h-1 cm-2 at a potential of -0.70 V. These results surpass those obtained using pristine Co3O4 and are comparable to those of state-of-the-art electrocatalysts. Moreover, the catalyst is further employed as the cathode catalyst to assemble a Zn-nitrate battery, giving a peak power density of 5.24 mW cm-2 and a high yield rate of 0.72 mg h-1 cm-2. Theoretical simulations further reveal that Zn-doping favors the adsorption and dissociation of nitrate and HMF species and reduces the energy barrier as well. Our work demonstrates the potential interest of Co3O4-based materials for the highly selective production of valuable feedstocks via ambient electrolysis.
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Bi-functional catalytic ability of an Ir-based catalyst for the acidic overall water splitting reaction was realized using tellurium nanorods as a support resulting from the special electronic coupling and synergism of the Ir and Te elements.
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Water splitting is a promising technique in the sustainable "green hydrogen" generation to meet energy demands of modern society. Its industrial application is heavily dependent on the development of novel catalysts with high performance and low cost for hydrogen evolution reaction (HER). As a typical non-precious metal, cobalt-based catalysts have gained tremendous attention in recent years and shown a great prospect of commercialization. However, the complexity of the composition and structure of newly-developed Co-based catalysts make it urgent to comprehensively retrospect and summarize their advance and design strategies. Hence, in this review, the reaction mechanism of HER is first introduced and the possible role of the Co component during electrocatalysis is discussed. Then, various design strategies that could effectively enhance the intrinsic activity are summarized, including surface vacancy engineering, heteroatom doping, phase engineering, facet regulation, heterostructure construction, and the support effect. The recent progress of the advanced Co-based HER electrocatalysts is discussed, emphasizing that the application of the above design strategies can significantly improve performance by regulating the electronic structure and optimizing the binding energy to the crucial intermediates. At last, the prospects and challenges of Co-based catalysts are shown according to the viewpoint from fundamental explorations to industrial applications.
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Proton exchange membrane (PEM) water electrolysis is considered a promising technology for green hydrogen production, and iridium (Ir)-based catalysts are the best materials for anodic oxygen evolution reactions (OER) owing to their high stability and anti-corrosion ability in a strong acid electrolyte. The properties of Ir-based nanocatalysts can be tuned by rational dimension engineering, which has received intensive attention recently for catalysis ability boosting. To achieve a comprehensive understanding of the structural and catalysis performance, herein, an overview of the recent progress was provided for Ir-based catalysts with different dimensions for the acidic OER. The promotional effect was first presented in terms of the nano-size effect, synergistic effect, and electronic effect based on the dimensional effect, then the latest progress of Ir-based catalysts classified into zero-dimensional (0D), one-dimensional (1D), two-dimensional (2D) and three-dimensional (3D) catalysts was introduced in detail; and the practical application of some typical examples in the real PEM water electrolyzers (PEMWE) was also presented. Finally, the problems and challenges faced by current dimensionally engineered Ir-based catalysts in acidic electrolytes were discussed. It is concluded that the increased surface area and catalytic active sites can be realized by dimensional engineering strategies, while the controllable synthesis of different dimensional structured catalysts is still a great challenge, and the correlation between structure and performance, especially for the structural evolution during the electrochemical operation process, should be probed in depth. Hopefully, this effort could help understand the progress of dimensional engineering of Ir-based catalysts in OER catalysis and contribute to the design and preparation of novel efficient Ir-based catalysts.
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The excessive emission of CO2 derived from the consumption of fossil fuels has caused severe energy and environmental crises. The electrochemical reduction of CO2 into value-added products such as CO not only reduces the CO2 concentration in the atmosphere but also promotes sustainable development in chemical engineering. Thus, tremendous work has been devoted to developing highly efficient catalysts for the selective CO2 reduction reaction (CO2RR). Recently, MOF-derived transition metal-based catalysts have shown great potential for the CO2RR due to their various compositions, adjustable structures, competitive ability, and acceptable cost. Herein, based on our work, a mini-review is proposed for an MOF-derived transition metal-based catalyst for the electrochemical reduction of CO2 to CO. The catalytic mechanism of the CO2RR was first introduced, and then we summarized and analyzed the MOF-derived transition metal-based catalysts in terms of MOF-derived single atomic metal-based catalysts and MOF-derived metal nanoparticle-based catalysts. Finally, we present the challenges and perspectives for the subject topic. Hopefully, this review could be helpful and instructive for the design and application of MOF-derived transition metal-based catalysts for the selective CO2RR to CO.