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21.
《International Journal of Hydrogen Energy》2022,47(32):14674-14686
Reformed exhaust gas recirculation technology has attracted great attention in internal combustion engines. A platform of an exhaust gas-fuel reformer connected with the marine LNG engine was set up for generating on-board hydrogen. Based on the platform, effects of the methane to oxygen ratio (M/O) and reformed exhaust gas ratio (REG) from the reformer and excess air ratio (λ) from the engine on the components, hydrogen yield, thermal efficiency and reforming process of the reformer were experimentally investigated. Results shown that hydrogen-rich gases (reformate) can be generated by reforming the mixture of engine exhaust gas (about 400 °C) and methane supplied via the reformer with Ni/Al2O3 catalyst, and the hydrogen concentration of reformate was between 6.2% and 12.6% by volume. The methane supplied rate and λ affected the components and temperature of the reactant in the reformer, while REG changed the gas hour space velocity during the exhaust gas-fuel reforming processes, resulting in the difference in the components of the reformate and thermal efficiency. At the present experimental condition, the highest H2 concentration reformate was generated under the M/O of 2.0, λ of 1.55 and REG of 6%. 相似文献
22.
《International Journal of Hydrogen Energy》2022,47(43):18587-18596
The development of cost-effective bifunctional catalysts with excellent performance and good stability is of great significance for overall water splitting. In this work, NiFe layered double hydroxides (LDHs) nanosheets are prepared on nickel foam by hydrothermal method, and then Ni2P(O)–Fe2P(O)/CeOx nanosheets are in situ synthesized by electrodeposition and phosphating on NiFe LDHs. The obtained self-supporting Ni2P(O)–Fe2P(O)/CeOx exhibit excellent catalytic performances in alkaline solution due to more active sites and fast electron transport. When the current density is 10 mA cm?2, the overpotential of hydrogen evolution reaction and oxygen evolution reaction are 75 mV and 268 mV, respectively. In addition, driven by two Ni2P(O)–Fe2P(O)/CeOx electrodes, the alkaline battery can reach 1.45 V at 10 mA cm?2. 相似文献
23.
《International Journal of Hydrogen Energy》2022,47(57):24169-24178
Oxygen reduction reaction (ORR), one of the key reactions for fuel cells and zinc-air batteries, should be improved for higher performance. Herein, we fabricated hollow Fe, Co, and nitrogen co-doped carbon (H-FeCo-NC) catalyst, which was prepared by carbonization of core-shell particles made of polypyrrole (PPy)-coated polystyrene (PS) spheres as cores and (Zn, Co) bimetallic-zeolitic imidazolate frameworks (ZnCoBZIFs) as shells. PPy was used as a nitrogen and a carbon source. The H-FeCo-NC catalyst had a high surface area of 324.08 m2 g?1 with uniformly distributed Fe and Co species, and excellent ORR performance with the half-wave potential of 0.888 V vs. reversible hydrogen electrode in alkaline media. Furthermore, the H-FeCo-NC catalyst demonstrated exceptional stability, durability, and tolerance to methanol crossover. 相似文献
24.
《International Journal of Hydrogen Energy》2022,47(71):30472-30483
Efficient electrocatalyst for alkaline oxygen evolution reaction is the critical core to the wide application of metal-air energy storage and water electrolysis hydrogen energy. Therefore, appropriate design of highly active and stable non-noble metal oxygen evolution electrocatalyst with good electronic structure and multilevel structure is both a goal and a challenge. Here, we report a Fe–Ni2P electrocatalyst (NiFeP-MOF) with multilevel structure, which was obtained by anion exchange on the basis of Fe–Ni(OH)2 (NiFe-MOF) grown on nickel foam in situ by solvothermal method. As expected, Fe substitution regulates the Ni oxidation state in the NiFeP-MOF and realizes electronic structure coupling, showing a highly active and stable oxygen evolution reaction (OER) in alkaline electrolyte solution. Specifically, the NiFeP-MOF demonstrates an ultralow overpotentials (232 mV, 10 mA cm?2; 267 mV 100 mA cm?2), respectively, an extremely small Tafel slope (34 mV dec?1). Separately, the electrocatalyst shows an excellent cycle stability at 10 mA cm?2 for 12 h (43,200 s). More importantly, this work come up with an available policy for the preparation of excellent alkaline hydrolysis electrolysis catalysts and air cathodes with excellent performance. 相似文献
25.
《International Journal of Hydrogen Energy》2022,47(73):31330-31341
A class of ruthenium-nickel alloy catalysts featured with nanoporous nanowires (NPNWs) were synthesized by a strategy combining rapid solidification with two-step dealloying. RuNi NPNWs exhibit excellent electrocatalytic activity and stability for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in which the RuNi-2500 NPNWs catalyst shows an OER overpotential of 327 mV to deliver a current density of 10 mA cm?2 and the RuNi-0 NPNWs catalyst requires the overpotential of 69 mV at 10 mA cm?2 showing the best HER activity in alkaline media. Moreover, the RuNi-1500 NPNWs catalyst was used as the bifunctional electrocatalyst in a two-electrode alkaline electrolyzer for water splitting, which exhibits a low cell voltage of 1.553 V and a long-term stability of 24 h at 10 mA cm?2, demonstrating that the RuNi NPNWs catalysts can be considered as promising bifunctional alkaline electrocatalysts. 相似文献
26.
《International Journal of Hydrogen Energy》2022,47(85):36294-36305
As proton-exchange membrane fuel cell technology has grown and developed, there has been increasing demand for the design of novel catalyst architectures to achieve high power density and realize wide commercialization. Herein, based on the two-dimensional biphenylene, we compare the oxygen reduction reaction (ORR) activity on the active sites with different biaxial lattice strains using first-principles calculations. The ORR free energy diagrams of biphenylene monolayers with varying lattice strains suggest that the biaxial tensile strains are unfavorable for catalytic activity. In contrast, the biaxial compressive strains could improve the catalytic performance. The biphenylene systems with the strain of ?2% ~ ?6% (S-0.02~-0.06) display overpotentials of 0.37–0.49 V. This performance is comparable to or better than the Pt (111) surface. The Bader charge transfer of adsorbed O species on various biaxial strain biphenylene catalysts could be a describer to examine the catalytic activity. The catalysts possessed the moderate transferred charge of O adsorbed species often promotes catalytic process and give the high catalysis efficiency. Overall, this work suggests that the lattice strain strategy can significantly enhance the catalytic activity of biphenylene materials and further provide guidance to design biphenylene-based catalysts in various chemical reactions. 相似文献
27.
《International Journal of Hydrogen Energy》2022,47(87):36831-36842
Two electron oxygen reduction reaction to produce hydrogen peroxide (H2O2) is a promising alternative technique to the multistep and high energy consumption anthraquinone process. Herein, Ni–Fe layered double hydroxide (NiFe-LDH) has been firstly demonstrated as an efficient bifunctional catalyst to prepare H2O2 by electrochemical oxygen reduction (2e? ORR) and oxygen evolution reaction (OER). Significantly, the NiFe-LDH catalyst possesses a high faraday efficiency of 88.75% for H2O2 preparation in alkaline media. Moreover, the NiFe-LDH catalyst exhibits excellent OER electrocatalytic property with small overpotential of 210 mV at 10 mA cm?2 and high stability in 1 M KOH solution. On this basis, a new reactor has been designed to electrolyze oxygen and generate hydrogen peroxide. Under the ultra-low cell voltage of 1 V, the H2O2 yield reaches to 47.62 mmol gcat?1 h?1. In order to evaluate the application potential of the bifunctional NiFe-LDH catalyst for H2O2 preparation, a 1.5 V dry battery has been used as the power supply, and the output of H2O2 reaches to 83.90 mmol gcat?1 h?1. The excellent electrocatalytic properties of 2e? ORR and OER make NiFe-LDH a promising bifunctional electrocatalyst for future commercialization. Moreover, the well-designed 2e? ORR-OER reactor provides a new strategy for portable production of H2O2. 相似文献
28.
基于CFD?DEM耦合方法,研究了颗粒在水室内的流动状态,分析了不同刀盘转速、粒子水通入量和水室出口角度对造粒过程的影响,发现提高刀盘转速、增加粒子水通入量和水室出口倾斜一定的角度都有利于水室内颗粒的排出。进一步研究了颗粒与碎屑在水室内的流动,发现在水室出口处二者的流动基本呈现出一定的分离角度。 相似文献
29.
《International Journal of Hydrogen Energy》2022,47(10):6710-6720
Herein, molybdenum disulfide nanoflakes decorated copper phthalocyanine microrods (CuPc-MoS2) are synthesized via two step simple hydrothermal method. The as synthesized hybrid along with pure molybdenum disulfide (MoS2) nanoflower and pure copper phthalocyanine (CuPc) microrods are well characterized by various techniques that confirm phase, morphology, elemental compositions etc. Next, electrocatalytic oxygen reduction reaction towards fuel cell is investigated in alkaline medium and obtained results proclaim that our CuPc-MoS2 heterostructure outperforms the other two constituent materials. Efficient oxygen reduction is achieved following four electron pathway by CuPc-MoS2 whereas partial reduction is done through two electron process by CuPc and MoS2 separately. Long-time durability test reveals almost 97.6% retention after 8000s that eventually dictate us that CuPc-MoS2 heterostructure can be the efficient cathode electrocatalyst for future generation fuel cell. 相似文献
30.
《International Journal of Hydrogen Energy》2022,47(12):7783-7792
Efficient and sustainable Janus catalysts toward hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are highly desirable for future hydrogen production via water electrolysis. Herein we report an active Janus electrocatalyst of amorphous-crystalline cobalt-molybdenum bimetallic phosphide heterostructured nanosheets on nickel foam (CoMoP/CoP/NF) for efficient electrolysis of alkaline water. As-reported CoMoP/CoP/NF consists of amorphous bimetal phosphide nanosheets doped with crystalline CoMoP/CoP heterostructured nanoparticles on NF. It can efficiently catalyze both HER (η = 127 mV@100 mA cm?2) and OER (η = 308 mV@100 mA cm?2) in alkaline electrolyte with long-term durability. Serving as anode and cathode of water electrolyzer, CoMoP/CoP/NF generates electrolytic current of 10, 50 and 100 mA cm?2 at low voltage of 1.50, 1.59, and 1.67 V, respectively. 相似文献