共查询到20条相似文献,搜索用时 31 毫秒
1.
《International Journal of Hydrogen Energy》2019,44(3):1774-1781
In this paper, ruthenium supported on nitrogen-doped porous carbon (Ru/NPC) catalyst is synthesized by a simple method of in situ reduction using ammonia borane (AB) as reducing agent. The composition and structure of Ru/NPC catalyst are systematically characterized. This catalyst can efficiently catalyze the hydrolysis of AB. The hydrogen production reaction is completed within about 90 s at a temperature of 298 K and the maximum rate of hydrogen production is 3276 ml·s−1·g−1 with a reduced activation energy of 24.95 kJ·mol−1. The turnover frequency (TOF) for hydrogen production is about 813 molH2·molRu−1·min−1. Moreover, this catalyst can be recycled with a well-maintained performance. After five cycles, the maximum rate of hydrogen generation is maintained at 2206 ml·s−1·g−1, corresponding to 67.3% of the initial catalytic activity. Our results suggest that Ru/NPC prepared by in situ reduction is a highly efficient catalyst for hydrolytic dehydrogenation of AB. 相似文献
2.
《International Journal of Hydrogen Energy》2020,45(16):9892-9902
In this study, Ru(0) nanoparticles supported in 2-hydroxyethyl starch-p-(2-Acrylamido-2-methyl-1-propanesulfonic acid) interpenetrating polymeric network (HES-p(AMPS) IPN) were synthesized as hydrogel networks containing hydroxyethyl starch, which is a natural polymer with oxygen donor atoms. The structure and morphology of the prepared HES-p(AMPS) IPN hydrogel and Ru@HES-p(AMPS) IPN catalyst were characterized using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), X-ray diffraction (XRD), and transmission electron microscope (TEM). Ru@HES-p(AMPS) IPN was used as catalyst for hydrogen production from the hydrolysis of ethylenediamine bisborane (EDAB). The activation parameters for the hydrolysis reaction of EDAB catalyzed by Ru@HES-p(AMPS) IPN were calculated as Ea = 38.92 kJ mol−1, ΔH# = 36.28 kJ mol−1, and ΔS# = −111.85 J mol−1 K−1, respectively. The TOF for the Ru@HES-p(AMPS) IPN catalyst was 2.253 mol H2 (mol Ru(0) min)−1. It was determined that Ru@HES-p(AMPS) IPN, a reusable catalyst, still had 81.5% catalytic activity after the 5th use. 相似文献
3.
《International Journal of Hydrogen Energy》2020,45(7):4390-4402
TiO2–CdS nanotubes (NTs) were used for the first time as a support to load metal nanoparticles (NPs) for the hydrolysis of ammonia borane (AB) which is a new strategy. The TiO2–CdS NTs support was first synthesized using a hydrothermal method, and then the CuNi NPs were loaded using a liquid-phase reduction method. The synthesized samples were characterized by XRD, SEM-EDS, TEM, XPS, ICP, UV–Vis, and PL analyses. The characterization results show that the CuNi NPs existed in the form of an alloy with a size of ~1.2 nm and uniformly dispersed on the support. Compared with their single metal counterparts, the bimetallic CuNi-supported catalysts showed a higher catalytic activity in the hydrolysis of AB under visible-light irradiation: Cu0·45Ni0·55/TiO2–CdS catalyst had the fastest hydrogen evolution rate with a high conversion frequency (TOF) of 25.9 molH2·molcat−1 min−1 at 25 °C and low activation energy of 32.8 kJ mol−1. Cu0.45Ni0.55/TiO2–CdS catalyst showed good recycle performance, maintaining 99.3% and 85.6% of the original hydrogen evolution rate even after five and ten recycles, respectively. Strong absorption of visible light, improved electron–hole separation efficiency, and metal synergy between Cu and Ni elements played a crucial role in improving the catalytic hydrolysis performance of AB. The catalyst prepared in this study provides a new strategy for the application of photocatalysts. 相似文献
4.
《International Journal of Hydrogen Energy》2014,39(35):19982-19989
Graphic carbon nitride prepared by the thermal decomposition of urea was used a catalyst support for the in situ immobilization of Ru nanoparticles (NPs) (Ru/g-C3N4). The catalytic property of Ru/g-C3N4 was investigated in the hydrolysis of ammonia borane (AB) in an aqueous solution under mild conditions. Results show that the in situ generated Ru NPs are well dispersed on the surface of g-C3N4 with a mean particle size of 2.8 nm. The catalytic performance for AB hydrolysis indicates that 3.28 wt% Ru/g-C3N4 exhibits excellent catalytic activity with a high turnover frequency number of 313.0 mol H2 (mol Ru·min)−1 at room temperature. This strategy may provide an eco-friendly catalytic system for developing a sustainable catalytic route to hydrogen production. 相似文献
5.
《International Journal of Hydrogen Energy》2023,48(39):14670-14680
Porous octahedral copper-based metal organic framework MOF-199 anchored with Ru, RuMo, RuP, and RuMoP nanoparticles (NPs) was fabricated by a simple liquid impregnation method and applied as a high-performance catalyst for the hydrolysis of ammonia borane (AB) at room temperature. Comparison of the catalytic activities of Ru@MOF-199, RuMo@MOF-199, RuP@MOF-199, and commercial Ru/C shows that RuMoP@MOF-199 owns a very high turnover frequency of 735.6 mol H2 min−1 (mol Ru)−1 and a low activation energy of 46.9 kJ/mol. Loading RuMoP NPs onto MOF-199 owing to synergistic effects, functional, size, and support effects kinetically facilitates the oxidative cleavage of attacked H-OH and elevate the catalytic performance. Moreover, this catalyst shows satisfied durability after five cycles for the hydrolytic dehydrogenation of AB. The novel structural features and efficient performance would provide an essential reference for the utilization of high-performance catalyst development. 相似文献
6.
《International Journal of Hydrogen Energy》2022,47(8):5230-5239
An effective strategy synthesis of Rh/meso-Al2O3 catalysts was demonstrated by mechanochemistry for hydrolytic dehydrogenation of ammonia borane (AB). These catalysts are characterized systematically by N2 adsorption-desorption isotherms, X-ray diffraction (XRD), X-ray photoelectron spectrometry (XPS), scanning electron microscope (SEM), and transmission electron microscope (TEM). The results show that the turnover frequency (TOF) and activation energy (Ea) are 246.8 molH2·molRh?1·min?1 and 47.9 kJ mol?1 for hydrolytic dehydrogenation of at 298 K catalyzed by Rh/Al2O3-CTAB-400, obviously higher than those previously reported catalysts. Furthermore, catalyst Rh/Al2O3-CTAB-400 can be recycled by simple centrifugal separation and the catalytic activity is still well maintained after five cycles. In addition, a plausible mechanism for hydrolytic dehydrogenation of AB has also been proposed. This mechanochemical synthesis method exhibits great application prospects for the preparation of heterogeneous catalysts. 相似文献
7.
《International Journal of Hydrogen Energy》2022,47(12):7793-7801
Developing efficient but facile strategies to modulate the catalytic activity of Ru deposited on metal oxides is of broad interest but remains challenging. Herein, we report the oxygen vacancies and morphological modulation of vacancy-rich Co3O4 stabilized Ru nanoparticles (NPs) (Ru/VO-Co3O4) to boost the catalytic activity and durability for hydrogen production from the hydrolysis of ammonia borane (AB). The well-defined and small-sized Ru NPs and VO-Co3O4 induced morphology transformation via in situ driving VO-Co3O4 to 2D nanosheets with abundant oxygen vacancies or Co2+ species considerably promote the catalytic activity and durability toward hydrogen evolution from AB hydrolysis. Specifically, the Ru/VO-Co3O4 pre-catalyst exhibits an excellent catalytic activity with a high turnover frequency of 2114 min?1 at 298 K. Meanwhile, the catalyst also shows a high durability toward AB hydrolysis with six successive cycles. This work establishes a facile but efficient strategy to construct high-performance catalysts for AB hydrolysis. 相似文献
8.
《International Journal of Hydrogen Energy》2023,48(78):30420-30434
The biohybrid Na-Alg@Ru catalyst was prepared as a result of stabilizing Ru(0) nanoparticles with biopolymer chains of sodium alginate. The in-situ prepared Ru(0) nanoparticles had an average particle size of 1.023 ± 0.097 nm. The monodisperse Ru(0) nanoparticles prepared with a very practical, inexpensive and rapid method were used as a catalyst in hydrogen production by the hydrolysis reaction of ammonia borane (AB). The Na-Alg@Ru catalyst containing 3 mg Ru(0) metal catalyzed the hydrolysis of 50 mM AB with 100% yield, and the activation energy (Ea) of the reaction was estimated as 61.05 kJ mol−1. In addition, the Na-Alg@Ru nanoparticles were prepared with acrylamide as p(AAm)/Na-Alg@Ru hydrogel films suitable for use in hydrogen production in fuel cells, which represents a battery-like environment, and used for hydrogen production from AB. Thus, it was shown that the catalysts prepared in a few nm size could easily be used in battery-like environments. 相似文献
9.
《International Journal of Hydrogen Energy》2020,45(3):1671-1680
A modified Stöber method is applied to synthesize the magnetic core-shell Fe3O4@SiO2 particles, followed by compositing a series of porous glucose-derived carbon with ZnCl2 as etchant. Then, ultrafine Pd nanoparticles (NPs) are successfully anchored to the resulting Fe3O4@SiO2-PC composites with an in-situ reduction strategy. The particle sizes of Pd NPs are mainly centered in the range of 2.3–4.3 nm in the as-prepared Pd/Fe3O4@SiO2-PC catalysts, owning a hierarchical porous structure with high specific surface area (SBET = 626.0 m2 g−1) and large pore volume (Vp = 0.61 cm3 g−1). Their catalytic behavior for the hydrogen generation from ammonia borane (AB) hydrolysis is investigated in details. The corresponding apparent activation energy is as low as 28.4 kJ mol−1 and the reaction orders with AB and Pd concentrations are near zero and 1.10 under the present conditions, respectively. In addition, the magnetic catalysts, which could be easily separated out by a magnet, are still highly active even after nine runs, revealing their excellent reusability. 相似文献
10.
Ziqian Wang Yalan Chen Yating He Weidong Jiang Yan Long Guangyin Fan 《International Journal of Hydrogen Energy》2021,46(21):11587-11596
Developing high-efficiency and low-cost catalysts for hydrogen evolution from hydrolysis of ammonia borane (AB) is significant and critical for the exploitation and utilization of hydrogen energy. Herein, the in-situ fabrication of well-dispersed and small bimetallic RuNi alloy nanoparticles (NPs) with tuned compositions and concomitant hydrolysis of AB are successfully achieved by using graphitic carbon nitride (g-C3N4) as a NP support without additional stabilizing ligands. The optimized Ru1Ni7.5/g-C3N4 catalyst exhibits an excellent catalytic activity with a high turnover frequency of 901 min?1 and an activation energy of 28.46 kJ mol?1 without any base additives, overtaking the activities of many previously reported catalysts for AB hydrolysis. The kinetic studies indicate that the AB hydrolysis over Ru1Ni7.5/g-C3N4 is first-order and zero-order reactions with respect to the catalyst and AB concentrations, respectively. Ru1Ni7.5/g-C3N4 has a good recyclability with 46% of the initial catalytic activity retained even after five runs. The high performance of Ru1Ni7.5/g-C3N4 should be assigned to the small-sized alloy NPs with abundant accessible active sites and the synergistic effect between the composition-tuned Ru–Ni bimetals. This work highlights a potentially powerful and simple strategy for preparing highly active bimetallic alloy catalysts for AB hydrolysis to generate hydrogen. 相似文献
11.
Ozgur OzayErk Inger Nahit AktasNurettin Sahiner 《International Journal of Hydrogen Energy》2011,36(14):8209-8216
In situ Co, Cu and Ni nanoparticles were synthesized by chemical reduction of the absorbed Co (II), Cu (II) and Ni (II) ions inside hydrogel networks prepared from 2-acrylamido-2-methyl-1-propansulfonic acid (AMPS) and were used as a catalyst system in the generation of hydrogen in hydrolysis of ammonia borane (AB). Several parameters affecting the hydrolysis reaction such as the type of the metal, the amount of catalyst, the initial concentration of AB, and temperature, were investigated. The activation energy values in the hydrolysis reaction of AB solution in the presence p(AMPS)-Co, p(AMPS)-Cu and p(AMPS)-Ni catalyst systems were calculated as Ea = 47.7 kJ mol−1, 48.8 kJ mol−1 and 52.8 kJ mol−1, respectively. Thus, the catalytic activity of the metal nanoparticles prepared inside the same hydrogel matrix was found to be Ni < Cu < Co. 相似文献
12.
《International Journal of Hydrogen Energy》2019,44(41):23267-23276
The hydrolysis of ammonia borane (NH3BH3) is recognized as an efficient way of hydrogen generation if it can be effectively catalyzed. In this work, a series of cobalt–molybdenum–boron (Co–Mo–B) nanoparticles (NPs) on copper (Cu) foil are introduced as catalysts for NH3BH3 hydrolysis by electroless deposition method. The influence of the depositing pH value on the catalytic property is investigated by adjusting the pH value ranged from 10.5 to 12.0. By optimizing the value to 11, the ultrafine Co–Mo–B NPs with the grain size around 4.3 nm show the best catalytic property for NH3BH3 hydrolysis. The hydrogen generation rate reaches 5818.0 mL·min−1·g−1 when the hydrolysis temperature is 298 K. The thermodynamic tests show that the lower activation energy (Ea) is estimated to be 59.3 kJ·mol−1. It can be found that the catalytic property in this work overtakes that of partial non-precious metal NPs, and is even better than some precious metal NPs previously reported. The hydrolysis reaction of NH3BH3 catalyzed by ultrafine Co–Mo–B NPs is a non-spontaneous process. In addition, the cycling ability of the ultrafine Co–Mo–B NPs is also studied and the results demonstrate that the catalyst is a recyclable one toward the hydrolysis of NH3BH3 under mild reaction conditions. 相似文献
13.
Min Hu Hua Wang Yi Wang Yun Zhang Jie Wu Bin Xu Daojiang Gao Jian Bi Guangyin Fan 《International Journal of Hydrogen Energy》2017,42(38):24142-24149
Effective catalysts for hydrogen generation from ammonia borane (AB) hydrolysis should be developed for the versatile applications of hydrogen. In this study, ruthenium nanoparticles (NPs) supported on alumina nanofibers (Ru/Al2O3-NFs) were synthesized by reducing the Ru(Ш) ions impregnated on Al2O3-NFs during AB hydrolysis. Results showed that the Ru NPs with an average size of 2.9 nm were uniformly dispersed on the Al2O3-NFs support. The as-synthesized Ru/Al2O3-NFs exhibited a high turnover frequency of 327 mol H2 (mol Ru min)?1 and an activation energy of 36.1 kJ mol?1 for AB hydrolysis at 25 °C. Kinetic studies showed that the AB hydrolysis catalyzed by Ru/Al2O3-NFs was a first-order reaction with regard to the Ru concentration and a zero-order reaction with respect to the AB concentration. The present work reveals that Ru/Al2O3-NFs show promise as a catalyst in developing a highly efficient hydrogen storage system for fuel cell applications. 相似文献
14.
《International Journal of Hydrogen Energy》2019,44(34):18848-18857
It is the first study to synthesize Co(II)-Schiff Base complex and to use it like a catalyst for potassium borohydride hydrolysis reaction to hydrogen production. Co(II)-complex is synthesized with CoCl2·6H2O and 5-Amino-2,4-dichlorophenol-3,5-di-tert-butylsalisylaldimine ligand. KBH4 hydrolysis reaction is studied according as percentage of KBH4, percentage of KOH, amount of Co-Schiff Base complex catalyst and temperature effects. Co-Schiff Base complex is highly effective catalyst and initial rates (Ro) of KBH4 hydrolysis reaction were 61220.00 and 99746.67 mL H2. g−1 cat. min−1 at 30 °C and 50 °C. Furthermore this study includes the kinetic calculations and for this reaction calculated activation energy is 17.56 kJ mol−1. 相似文献
15.
Fangyuan Qiu Yiling Dai Li Li Changchang XuYanan Huang Chengcheng ChenYijing Wang Lifang JiaoHuatang Yuan 《International Journal of Hydrogen Energy》2014
Non-noble Cu@FeCo core–shell nanoparticles (NPs) containing Cu cores and FeCo shells have been successfully in situ synthesized via a facile chemical reduction method. The NPs exerted composition-dependent activities towards the catalytic hydrolysis of ammonia borane (NH3BH3, AB). Among them, the Cu0.3@Fe0.1Co0.6 NPs showed the best catalytic activity, with which the max hydrogen generation rate of AB can reach to 6674.2 mL min−1 g−1 at 298 K. Kinetic studies demonstrated that the hydrolysis of AB catalysed by Cu0.3@Fe0.1Co0.6 NPs was the first order with respect to the catalyst concentration. The activation energy (Ea) was calculated to be 38.75 kJ mol−1. Furthermore, the TOF value (mol of H2. (mol of catalyst. min)−1) of Cu0.3@Fe0.1Co0.6 NPs was 10.5, which was one of the best catalysts in the previous reports. The enhanced catalytic activity was largely attributed to the preferable synergistic effect of Cu, Fe and Co in the special core–shell structured NPs. 相似文献
16.
《International Journal of Hydrogen Energy》2019,44(31):16548-16556
Development of supported ligand-free ultrafine Rh nanocatalysts for efficient catalytic hydrogen evolution from ammonia borane (AB) is of importance but remains a tremendous challenge. Here, ultrafine and ligand-free Rh nanoparticles (NPs) (2.19 nm in diameter) were in-situ decorated on porous phosphorus-functionalized carbon (PPC) prepared by pyrolyzing hyper-cross-linked networks of triphenylphosphine and benzene. The resultant Rh/PPC showed excellent hydrogen production activity from AB hydrolysis (Turnover frequency: 806 min−1). Kinetic investigations indicated that AB hydrolysis using Rh/PPC exhibited first-order and zero-order reactions with Rh and AB concentrations, respectively. Activation energy (Ea) toward hydrogen generation from AB with Rh/PPC is as low as 22.7 kJ/mol. The Rh/PPC catalyst was recyclable and reusable for at least four times. The oxygen- and phosphorus-functional groups are beneficial for the affinity of Rh complex on the PPC surface, resulting in ultrafine and ligand-free Rh NPs with high dispersity and ability to supply abundant surface accessibility to catalytically active sites for AB hydrolysis. This study proposes a feasible approach for the synthesis of ultrafine and ligand-free metal NPs supported on heteroatom-doped carbon by using hyper-cross-linked networks. 相似文献
17.
《International Journal of Hydrogen Energy》2023,48(48):18245-18256
Ammonia borane (AB, NH3BH3) hydrolysis is an effective way to safely generate hydrogen. However, a suitable catalyst is indispensable because the hydrolytic reaction cannot take place kinetically at room temperature. In this work, CuNi alloy nanoparticles are immobilized on porous graphitic carbon nitride (g-C3N4) with a facile adsorption-chemical reduction method. Benefiting from the hierarchical porous structure of the support, the interesting alloy effect of Cu and Ni, as well as the synergistic effect between g-C3N4 and the CuNi alloys, the optimal Cu0·7Ni0.3/g-C3N4 catalyst displays excellent catalytic performance in AB hydrolysis, such as high turnover frequency (2.08 min−1, at 303 K), low apparent activation energy (23.58 kJ mol−1), and satisfactory durability. The results verify that the optimal catalyst has particular potential in hydrogen energy utilization due to the advantages such as the facile preparation procedure, low cost and excellent catalytic behavior. 相似文献
18.
A kind of Ru-based catalyst was prepared by using a natural polyphenolic polymer (bayberry tannin, BT) immobilized on collagen fiber (CF) as the stabilizer and carrier of Ru nanoparticles (NPs) and characterized to detect its main physicochemical properties. The CF-BT-Ru catalyst was found to be in an orderly fiber morphology with Ru NPs with about diameter of 2.6 nm highly distributed on the surface. The research on catalytic activity of CF-BT-Ru focused on the hydrolysis of ammonia borane (AB) to produce hydrogen. The influences of Ru loading, Ru dosage, AB concentration and temperature on the catalytic AB hydrolysis were investigated in detail, and the related thermodynamic parameters (activation energy (Ea), activation entropy (△S), activation enthalpy (△H) and Gibbs free energy (△G)) were calculated. The experimental results indicated that CF-BT-Ru exhibited high catalytic activity. Its turnover frequency (TOF) was as high as 322 and Ea was as low as 32.41 kJ mol?1 for AB hydrolysis. Moreover, CF-BT-Ru exhibited satisfied reusability and stability. Its activity lost only one-fifth and no obvious agglomeration and leakage of Ru NPs were found after repeated use for 5 times. 相似文献
19.
Rui Lu Min Hu Caili Xu Yi Wang Yun Zhang Bin Xu Daojiang Gao Jian Bi Guangyin Fan 《International Journal of Hydrogen Energy》2018,43(14):7038-7045
Developing effective catalysts for hydrogen evolution from hydrolysis of ammonia borane (AB) is of great significance considering the useful applications of hydrogen. Herein, graphitic carbon nitride (g-C3N4) prepared through the simply pyrolysis of urea was employed as a support for Rh nanoparticles (NPs) stabilization. The in-situ generated Rh NPs supported on g-C3N4 with an average size of 3.1 nm were investigated as catalysts for hydrogen generation from the hydrolysis of AB under mild conditions. The Rh/g-C3N4 catalyst exhibits a high turnover frequency of 969 mol H2· (min·molRh)?1 and a low activation energy of 24.2 kJ/mol. The results of the kinetic studies show that the catalytic hydrolysis of AB over the Rh/g-C3N4 catalyst is a zero-order reaction with the AB concentration and a first-order reaction with the Rh concentration. This work demonstrates that g-C3N4 is a useful support to design and synthesis of effective Rh-based catalyst for hydrogen-based applications. 相似文献
20.
Addressed herein is the catalysis of reduced graphene oxide-supported monodisperse NiPd alloy nanoparticles (NPs) (rGO-NiPd) in the hydrolytic dehydrogenation of ammonia borane (AB). This is the first example of the use of NiPd alloy NPs as catalyst in the hydrolytic dehydrogenation of AB. Monodisperse NiPd alloy NPs (3.5 nm) were synthesized by co-reduction of nickel(II) acetate and palladium(II) acetylacetonate in oleylamine (OAm) and borane-tert-butylamine complex (BTB) at 100 °C. The current recipe allowed to control the composition of NiPd alloy NPs and to study the composition-controlled catalysis of rGO-NiPd in the hydrolytic dehydrogenation of AB. Among the all compositions tested, the Ni30Pd70 was the most active one with the turnover frequency of 28.7 min−1. The rGO-Ni30Pd70 were also durable catalysts in the hydrolytic dehydrogenation of AB providing 3650 total turnovers in 35 h and reused at six times without deactivation. The detailed reaction kinetics of hydrolytic dehydrogenation of AB revealed that the reaction proceeds first order with respect to the NiPd concentration and zeroth order with respect to the AB concentration. The apparent activation energy of the catalytic dehydrogenation of AB was also calculated to be Eaapp = 45 ± 2 kJ*mol−1. 相似文献