Hydrolysis Of Sodium Borohydride Research Articles

Catalytic hydrolysis of sodium borohydride solution for hydrogen production using thermal plasma synthesized nickel nanoparticles

In the present study nickel nanoparticles were synthesized by thermal plasma route. In this method we obtained highly crystalline almost spherical nanoparticles with maximum number of particles having size around 30–50 nm. These nanoparticles were thoroughly characterized and employed as a catalyst for hydrogen production using hydrolysis of sodium borohydride (NaBH4). The effect of initial concentration of NaBH4, pH and temperature of solution on the rate of hydrogen production was investigated. Nickel nanoparticles exhibits first order reaction with respect to NaBH4 concentration at elevated temperatures. After hydrolysis, the nickel nanoparticles showed presences of B–O and B–OH species on the nickel surface. The catalyst was found to be stable during 5 sequential cycles of test.

Highly active and durable catalyst for hydrogen generation by the NaBH4 hydrolysis reaction: CoWB/NF nanodendrite with an acicular array structure

Sodium borohydride (NaBH4) hydrolysis is a promising technology to produce high-purity hydrogen (H2) on-site for fuel cells. However, the widespread applications of this technology are hampered by the low catalytic activity and poor stability of the catalyst for hydrogen production. To develop a low-cost catalyst with high activity and good stability, a novel CoWB catalyst supported by nickel foam was prepared by the pulse electrodeposition method for H2 production from a NaBH4 alkaline solution. The SEM results revealed that in the special microstructure of nanodendrites with acicular arrays, CoWB was uniformly plated on the surface of the Ni foam (NF) substrate and firmly adhered to the surface. The tungsten doping decreased the activation energy to as low as 18.15 kJ mol−1. The CoWB/NF catalyst exhibited higher hydrogen producing performance, and the hydrogen generation rate (HGR) reached 14.13 L min−1·g−1 cat, which was comparable to that of the noble metal catalyst. More importantly, the catalyst demonstrated very good stability, as the catalytic activity was maintained at 82% of its initial activity after 800 h of usage. The CoWB/NF catalyst of the hydrogen generator contributed to the generation of hydrogen with 99.9871% purity at an HGR of 1.07 L/min. This study demonstrated that the novel CoWB/NF catalyst is very promising for hydrogen production from the NaBH4 hydrolysis reaction.

CoB doped acid modified zeolite catalyst for enhanced hydrogen release from sodium borohydride hydrolysis

Cobalt-boron (CoB) catalyst supported on zeolite modified with hydrochloric acid (CoB-zeolite-HCl) and zeolite modified with acetic acid (CoB-zeolite-CH3COOH) is prepared for the hydrogen (H2) release from sodium borohydride (NaBH4). The supported catalyst samples were characterized by X-ray diffraction spectroscopy (XRD), scanning electron microscope (SEM), Fourier transforms infrared spectroscopy (FTIR), nitrogen adsorption and, inductively coupled plasma optical emission spectroscopy (ICP-OES). The effects of Co metal loading, NaBH4 concentration, NaOH concentration, temperature, and reusability on the catalytic performance of the CoB-zeolite-HCl catalyst were investigated. The completion time of the reaction using the raw zeolite supported CoB catalyst was about 265 min. However, the completion time of the reaction using the CoB-zeolite-HCl catalyst was decreased to about 80 min. BET surface area values showed that there is a 7-fold increase in the specific surface area for the zeolite activated with HCl compared to the BET surface area for the raw zeolite. The activation energy (Ea) of the catalyzed reaction was 42.45 kJ mol−1.

Highly active, robust and reusable micro-/mesoporous TiN/Si3N4 nanocomposite-based catalysts for clean energy: Understanding the key role of TiN nanoclusters and amorphous Si3N4 matrix in the performance of the catalyst system

Herein, we developed a precursor approach toward the design of a titanium nitride (TiN)/silicon nitride (Si3N4) nanocomposite with an activated carbon monolith as a support matrix forming a highly micro-/mesoporous component to be used as a Pt support for the catalytic hydrolysis of sodium borohydride (NaBH4) as a model reaction. The experimental data demonstrated that the amorphous Si3N4 matrix, the strong Pt-TiN nanocluster interaction and the synergistic effects between the three components contributed to the improved performance of the catalyst system. Thus, the use of this TiN/Si3N4 nanocomposite allowed to significantly reducing the noble metal loading (only ∼1 wt% of Pt) for the complete and fast dehydrogenation of NaBH4 under alkaline conditions at 80 °C. Additionally, the catalytic system displayed an excellent robustness and durability to offer reusability without collapsing and performance decrease under the harsh conditions imposed by the reaction.

Hydrogen generation from sodium borohydride by sulfonated polymers

In this study, hydrogen generation from sodium borohydride was achieved via disulfonated poly(arylene ether sulfone) copolymers. Protons on the sulfone groups of copolymers catalyzed the hydrolysis of sodium borohydride and produced hydrogen. The hydrogen generation rate was affected by the disulfonation degree, which is an indication of the amount of sulfone groups in the copolymer. The rate showed an increment as the disulfonation degree increased. Additionally, the hydrogen generation rate was a function of both the copolymer amount and borohydride concentration. Moreover, the reaction had relatively low activation energy and was calculated from the Arrhenius plot as 19.2 kJ mol−1. Furthermore, copolymers were found highly reusable with optimized treatment conditions and could preserve their catalytic activity up to 25 runs.

Hydrogen generation by catalytic hydrolysis of sodium borohydride using the nano-bimetallic catalysts supported on the core-shell magnetic nanocomposite of activated carbon

The purpose of this study were to prepare the novel supported bimetallic cobalt-nickel catalysts on the core-shell magnetic nanocomposite of activated carbon derived from wood by sequential and co-deposition-precipitation. The performance of the prepared catalyst was evaluated for the hydrogen generation from hydrolysis of sodium borohydride. The magnetic catalysts were characterized by applying the XRD, XPS, FTIR, FESEM, TEM, ICP, BET and VSM tests. The hydrogen generation rate was increased with the reduction of calcination temperature. The well dispersed magnetic nanoparticles were fabricated with average size below of 30 nm which was confirmed by TEM, FESEM and XRD results. The activity of the prepared samples with respect to the preparation method was illustrated to follow a specific order: Co/Ni/MWAC > Ni/Co/MWAC > Co–Ni/MWAC. The developed model derived from design of experiments could correlate the operating parameters with the experimental data while the correlation coefficient was achieved to be 0.99. The hydrogen generation rate was increased with increasing the reaction temperature and the concentration of sodium borohydride in the alkaline solutions. The hydrogen generation rate was measured to be 740.70 ml min−1. gcat−1 in the presence of the Co/Ni/MWAC at 30 °C. The experimental study also indicated that the hydrolysis of sodium borohydride was a zero order type reaction and the activation energy was calculated 40.70 kJ mol−1. The stability of the prepared sample was also investigated for six cycles which showed the acceptable performance of the synthesized catalyst for the practical applications.

Salts Induced Formation of Hierarchical Porous ZIF‐8 and Their Applications for CO2 Sorption and Hydrogen Generation via NaBH4 Hydrolysis

AbstractDespite the great potential of two different pore regimes (hierarchical porous (HP) structure), HP‐zeolitic imidazolate frameworks‐8 (HPZIF‐8) can be efficient catalysts for hydrogen generation via hydride hydrolysis, and as adsorbents for CO2 gas adsorption. Herein, HPZIF‐8, and leaf‐like ZIF (ZIF‐L) are synthesized via a simple and environmentally friendly procedure using layered hydroxide nitrate of zinc (Z5HN) as a metal source and simple inorganic salt as a modulator. Z5HN nanosheets undergo topotactic transformation to simonkolleite (Zn5(OH)8Cl2·H2O) that can be converted to the pure phase of HPZIF‐8. The concentration of the salts tunes the textural properties of the final product. Applications of HPZIF‐8 and ZIF‐L for CO2 sorption exhibit excellent adsorption properties with increases of 25% due to the presence of cations in the frameworks. ZIF‐8 shows exceptional high catalytic activity for hydrogen generation via the hydrolysis of sodium borohydride. The simple synthesis of ZIF‐8 as well as their good performance as adsorbent and catalyst ensure the potential for industrial and commercial uses.

Hydrogen generation from catalytic hydrolysis of sodium borohydride by a Cu and Mo promoted Co catalyst

Catalytic hydrolysis of chemical hydrides with the use of NaBH4 is a safe and effective way to provide hydrogen fuel for new energy vehicles and portable electronic devices. Herein we developed a Cu and Mo promoted Co hierarchical composites (Co1−xCuxMoO4) for hydrolysis of NaBH4 via an easy synthesis route. FESEM analysis depicts that the morphology of Co1−xCuxMoO4 hierarchical composites varied significantly from irregular microsphere to marigold microsphere to rose like morphology with the increase in Cu (x) ratio with respect to Co (1 − x). Flower-like morphological architecture and crystal configuration empower the supported catalyst to exhibit a remarkable catalytic activity and outstanding catalytic activity was obtained for marigold-like Co0.9Cu0.1MoO4 catalyst with an H2 generation rate of 1005.7 mL min−1 g−1, which confirms existence of synergistic effect between Co, Cu and Mo. Lower loading of Cu in Co1−xCuxMoO4 supported the active sites of Co to increase its catalytic activity. Additionally, the catalyst exhibits good recyclability after five successive runs of hydrolytic reaction, making it a robust catalyst for hydrolysis of NaBH4 and could be considered as a potential catalyst for portable hydrogen fuel systems.

Structural and catalytic properties of Ni-, Co-spinel, and its composites

In the context of a modern research, revise, and development of alternative energy sources, electrochemical systems occupy a significant and promising niche. An open for research issue related to electrochemical energy sources is the development and search for efficient, environmentally friendly, and cost-effective catalysts for fuel cell. A promising and applicable direction in this area is the investigation of mixed-type oxide catalysts, in particular catalysts with a spinel structure. In the present work, the spinel of NiCo2O4 composition and its composites, obtained by a simple co-precipitation method, were investigated using SEM, XRD, and N2 low-temperature adsorption–desorption methods. The catalytic activity of all the synthesized samples was studied during the sodium borohydride hydrolysis reaction. A significant correlation was found between the features of the obtained samples porous structure and their catalytic properties. As the data obtained showed, the synthesized samples have all the properties of an effective catalyst that can be used in electrochemical energy sources.

Correlation between partial inhibition of hydrogen evolution using thiourea and catalytic activity of AB5-type hydrogen storage alloy towards borohydride electrooxidation

Direct borohydride fuel cells (DBFCs) are devices which directly convert the chemical energy stored in the borohydride ion and oxidant into electrical energy as a result of redox reactions. Unfortunately, a significant amount of fuel is lost as a result of the undesirable hydrolysis reaction. The selection of an efficient borohydride hydrolysis inhibitor requires detailed knowledge regarding the interaction mechanism between the inhibitor molecule and electrode surface. In this study, various amounts of thiourea additives (0.011–1.600 mM) were tested to select the best fuel composition for DBFC application. When AB5-type anode was used, only partial inhibition of sodium borohydride hydrolysis was a desirable phenomenon. Partially released hydrogen results in the improvement of catalytic properties of the alloy. The addition of 0.016 mM thiourea does not inhibit the oxidation of borohydride, on the contrary, it increases the practical capacity from 27% to 41% of the theoretical value. Moreover, we indicate that the addition of thiourea prevents corrosion as well as degradation of the electrode surface. Pressure measurements confirmed the effectiveness of thiourea in relation to hydrogen evolution, while X-ray photoelectron spectroscopy and Raman spectroscopy revealed that the electrode surface was not poisoned.

Co−O−P composite nanocatalysts for hydrogen generation from the hydrolysis of alkaline sodium borohydride solution

In recent years, catalytic hydrolysis of sodium borohydride is considered to be a promising approach for hydrogen generation towards fuel cell devices, and highly efficient and noble-metal-free catalysts have attracted increasing attention. In our present work, Co3O4 nanocubes are synthesized by solvothermal method, and then vapor-phase phosphorization treatment is carried out for the preparation of novel Co−O−P composite nanocatalysts composed of multiple active centers including Co, CoO, and Co2P. For catalyst characterization, field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), energy dispersive spectrometry (EDS), X-ray diffraction (XRD) and X-ray photoelectric spectroscopy (XPS) are conducted. Optimal conditions for catalyst preparation and application were investigated in detail. At room temperature (25 °C), maximum hydrogen generation rate (HGR) is measured to be 4.85 L min−1 g−1 using a 4 wt% NaBH4 − 8 wt% NaOH solution, which is much higher than that of conventional catalysts with single component reported in literature. It is found that HGR remarkably increases with the increasing of reaction temperature, and apparent activation energy for catalytic hydrolysis of NaBH4 is calculated to be 63 kJ mol−1. After reusing for five times, the Co−O−P composite nanocatalysts still retains 78% of the initial activity.

Cobalt–copper–boron nanoparticles as catalysts for the efficient hydrolysis of alkaline sodium borohydride solution

Developing non-precious metal catalysts with high activity is crucial for the extensive applications of the proton exchange membrane fuel cell (PEMFC). Herein, we have prepared cobalt–copper–boron (Co–Cu–B) nanoparticles by a modified chemical reduction route where Ni foam was used as an initiation medium for the efficient hydrolysis of alkaline sodium borohydride (NaBH4) solution. The influence of the synthetic condition (such as Cu2+ concentration, pH value and the concentration of reducing agent) on the catalytic activities has been explored. The catalytic hydrolytic tests reveal that the as-obtained Co–Cu–B nanoparticles with hollow spherical structure shows highly efficient catalytic activity, affording a hydrogen generation rate (HGR) of 3554.2 mLH2·gcatal.−1·min−1 under room temperature, and a lower activation energy of 52.0 kJ· mol−1, which overtakes the activities of previous reported most non-precious metal catalysts, even some precious catalysts. The kinetics results show that the catalytic hydrolysis process of alkaline NaBH4 solution is a zero-order reaction in view of the amount of Co–Cu–B catalyst, meaning that the reaction rate is independent of the catalyst amount. This study offers us a promising non-precious metal catalyst toward dehydrogenation from the hydrolysis of NaBH4 to further speed up the application steps.

Protonated Poly(ethylene imine)-Coated Silica Nanoparticles for Promoting Hydrogen Generation by Hydrolysis of Sodium Borohydride.

Invited for this month's cover is the group of Dr. Hua Dong from Chengdu University of Technology, China. The cover picture shows a nonmetal catalyst (SiO2 @H+ PEI) that promotes hydrogen production by hydrolysis of NaBH4 . This newly developed catalyst, which is fabricated by covalently modifying SiO2 nanoparticles with protonated poly(ethylene imime), provides a promising choice for the cheap and efficient catalysis of NaBH4 hydrolysis. Read the full text of the article at 10.1002/cplu.201900609.

Preparation of the efficient nano-bimetallic cobalt-nickel catalysts supported on the various magnetic substrates for hydrogen generation from hydrolysis of sodium borohydride in alkaline solutions

The heterogeneous catalytic hydrolysis of NaBH4 over the various bimetallic cobalt-nickel catalysts supported on the magnetic substrates was studied to understand their catalytic performances. Bentonite, zeolite (clinoptilolite), walnut based activated carbon, and Scharlau activated carbon (commercial sample) were used for the preparation of the magnetic catalysts. Despite the interest, no one to the best of our knowledge has studied the synthesize of the efficient bimetallic catalyst over the magnetic bentonite. The physico-chemical properties of the catalysts were evaluated by using XRD, FTIR, FESEM, TEM, BET, and VSM tests. The characterization of the catalysts indicated that the co-precipitation along with hydrazine is an appropriate method for the synthesis of the superparamagnetic nanoparticles over the porous substrates with sizes less than 30 nm. The highest magnetic strength was achieved to be 30.49 emu/g for the samples supported on the magnetic bentonite. The various operating conditions were also investigated including reaction temperature, NaOH, and NaBH4 content. The results illustrated that the hydrolysis of NaBH4 to hydrogen was a zero-order type reaction with respect to the NaBH4 content. The maximum hydrogen generation rate was measured to be 186 mL.min−1.gcat−1 in the presence of the bimetallic cobalt-nickel catalyst supported on the magnetic bentonite. The minimum activation energies were also calculated to be 37.62 and 44.98 kJ.mol−1 over the samples supported on the magnetic zeolite and bentonite, respectively. The reusability of the catalyst was also investigated in six cycles.

Fabrication of amorphous Co–Cr–B and catalytic sodium borohydride hydrolysis for hydrogen generation

Abstract

Encapsulated cobalt nanoparticles as a recoverable catalyst for the hydrolysis of sodium borohydride

The significant challenges encountered when replacing precious-metal-based catalysts in the hydrolysis of sodium borohydride (NaBH4) are related to the low durability and efficiency of nonprecious metals. In this study, we synthesized nitrogen-doped mesoporous graphitic carbon encapsulated cobalt nanoparticles (Co@NMGC) with a core–shell structure by the carbonization of ethylenediaminetetraacetic acid (EDTA)-derived carbon. These structures were then used as catalysts for the hydrolisis of NaBH4. Among different calcination temperatures, 500 ​°C resulted in the best catalytic activity, with a hydrogen production rate of 3575 ​mL ​min−1 g−1 at 25 ​± ​0.1 ​°C and low activation energy of 35.2 ​kJ ​mol−1 for NaBH4 hydrolysis. The maximum hydrogen production rate using the cobalt-based complex catalyst was about three-fold that achieved using the pure cobalt catalyst. We found that the complex catalyst showed high durability, retaining 82.5% of the initial catalytic activity after 20 hydrolysis cycles. The catalyst was also magnetic, making it 100% recyclable. Density functional theory (DFT) calculations showed that the graphitic carbon shell promoted electron penetration from the Co nanoparticles into the graphitic carbon surface, which prevented oxidation of the Co nanoparticles, while the Co core provided better conductivity. This work provides a novel method for the synthesis of shelled-structure catalysts, which have potential applications in the hydrolysis of sodium borohydride.

Silver nanoparticle embedded anionic crosslinked copolymer hydrogels: an efficient catalyst

The present study aimed to synthesize poly(2-acrylamido-2-methyl-1-propansulfonic acid-co-acrylic acid), p(AMPS-c-AA), embedded with silver nanoparticles and to investigate their potential in catalysis. The hydrogels were prepared from 2-acrylamido-2-methyl-1-propansulfonic acid (AMPS) and acrylic acid (AA) monomers via free radical polymerization reaction technique in the mild reaction condition and silver nanoparticles were fabricated within hydrogel by reducing Ag (I) ions using NaBH4 as reducing agent. The synthesized p(AMPS-c-AA) hydrogel was characterized by Fourier transform infrared (FT-IR), scanning electron microscopy (SEM) and nuclear magnetic resonance spectroscopy (NMR). Silver nanoparticles embedded in p(AMPS-c-AA) hydrogel were visualized by transmission electron microscopy (TEM). The metal content of composites was estimated via atomic absorption spectroscopy (AAS). Applications of this synthesized hydrogel was also investigated by using as a catalyst in the reduction of 4-nitrophenol and H2 generation from hydrolysis of sodium borohydride (NaBH4). The activation energies, enthalpy, and entropy for 4-NP reduction and NaBH4 hydrolysis catalyzed by composite were determined. P(AMPS-c-AA)-Ag composite was also used as catalyst in the aerobic oxidation of alcohols by emphasizing the effects of different parameters such as temperature, substituent effect, etc. Finally, recycling of the poly(AMPS-c-AA) hydrogel fabricated with Ag nanoparticles was carried out for four consecutive cycles and no significant loss in catalytic activity was observed.

UiO-66 as a catalyst for hydrogen production via the hydrolysis of sodium borohydride.

The exploration of a highly efficient catalyst for the hydrolysis of sodium borohydride (NaBH4) is a valuable step toward a hydrogen economy. UiO-66 (Universitetet i Oslo) was synthesized via a solvothermal method using acetic acid as a modulator. The material was characterized using X-ray diffraction (XRD), nitrogen adsorption-desorption isotherms, Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), temperature-programmed desorption (TPD), and transmission electron microscopy (TEM). Data analysis reveals the formation of a pure and highly crystalline phase of UiO-66 with the Brunauer-Emmett-Teller (BET) and Langmuir specific surface areas of 1125 m2 g-1, and 1250 m2 g-1, respectively. UiO-66 was analysed as a catalyst for hydrogen generation via the hydrolysis of NaBH4. The effect of the NaBH4 amount and catalyst loading was investigated. The reaction time decreased with an increase of the amount of NaBH4 or UiO-66. UiO-66 exhibited an average hydrogen generation rate of 6200 mL min-1 g-1. The high catalytic performance of UiO-66 could be due to its large surface area and acidic sites. The results suggested that UiO-66 showed high potential to catalyze the hydrogen production via the hydrolysis of hydrides.

PVP-Protected Pt-Ru Nanoparticles as Highly Efficient Catalysts for Hydrogen Generation from Hydrolysis of Sodium Borohydride

PVP-Protected Pt-Ru Nanoparticles as Highly Efficient Catalysts for Hydrogen Generation from Hydrolysis of Sodium Borohydride

Protonated Poly(ethylene imine)-Coated Silica Nanoparticles for Promoting Hydrogen Generation from the Hydrolysis of Sodium Borohydride.

Nonmetal catalysts are attracting a great deal of attention because of their advantages including high activity, low cost, and environmental friendliness. In this work, a nonmetal catalyst for NaBH4 hydrolysis was fabricated through covalent modification of silica nanoparticles with protonated poly(ethylene imine). The successful formation of the catalyst was verified by transmission electron microscopy, thermogravimetric analysis, and Fourier transform infrared spectroscopy. The fabricated catalyst shows excellent activity in catalyzing NaBH4 hydrolysis reactions. The hydrolysis of 15 mg NaBH4 catalyzed by 50 mg catalyst could provide a hydrogen generation rate as high as 117.53 mL min-1 at 20 °C. Although the catalytic activity decreased after use, it could be restored easily by regenerating in acetic acid solution.