NaBH4 Hydrolysis Research Articles

Dislocation-driven high catalytic performance of FeCoNiCrMn high-entropy alloy for the hydrolysis of NaBH4

A high-entropy alloy Fe10Co10Ni10Cr10Mn60 ribbon catalyst with a face-centered cubic structure was designed by using Co and Ni as the main catalytic elements and combining various co-catalytic elements, such as Fe, Mn, and Cr. Substantial element selective corrosion occurs during the acid solution corrosion process, which induces the exposure of many Co and Ni atoms, increases the specific surface area, and further results in the formation of many vacancies and dislocations. This unique structure generates a positive electron effect, that is the peaks of Ni2p3/2 and Co2p3/2 shift to lower binding energies, namely, approximately 1 eV for Ni and 0.8 eV for Co, indicating the Co and Ni enrich electrons. The catalyst shows an excellent catalytic performance for the hydrolysis of NaBH4 after corrosion for 90 s, whose hydrogen production rate approaches 18.46 l/(m2·min). This work opens up a direction for the application of the macroscopic scale high-entropy alloy in the catalytic hydrogen field.

Efficient hydrogen generation from the NaBH4 hydrolysis by amorphous Co–Mo–B alloy supported on reduced graphene oxide

Efficient hydrogen generation from the NaBH4 hydrolysis by amorphous Co–Mo–B alloy supported on reduced graphene oxide

Cobalt nanoparticle supported on layered double hydroxide: Effect of nanoparticle size on catalytic hydrogen production by NaBH4 hydrolysis

Catalytic hydrolysis of sodium borohydride (NaBH4) is a promising method to provide clean hydrogen (H2) energy for portable devices. Therefore, designing a non-noble metal catalyst that performs well in this hydrolysis is essential. Cobalt-nanoparticles (Co-NPs) supported on magnesium-aluminium layered double hydroxide (LDH) with various mean diameter were synthesized by changing concentration of cobalt-citrate anion (Co-citrate) precursor used for ion exchange with the LDH host. Then the Co-citrate intercalated LDHs were reduced with NaBH4 to form Co-NPs. Evidence of successful intercalation was shown by X-ray diffraction (XRD) and Fourier-Transform Infrared spectroscopy (FT-IR). Transmission Electron Microscope (TEM) and Scanning TEM (STEM) observations revealed that Co-NPs were in metallic state and their mean diameter increased with the concentration of Co-citrate solution. Nitrogen physisorption isotherms showed that the surface structure of LDHs transformed from non-porous to mesoporous after chemical reduction, which indicated that the Co-NPs were formed in the interlayer of LDHs. Catalytic hydrolysis of NaBH4 at 25 °C clarified that the catalyst synthesized from 6 mM Co-citrate solution showed the highest H2 generation rate of 4520 ± 251 mL min−1·gCo−1, indicating the catalyst had the optimum size of Co-NP. This activity could be considered relatively higher compared to unsupported cobalt and many other supported cobalt-base catalysts previously reported. It was also clearly shown that size of Co-NPs supported on LDH could be a significant parameter as it allowed better accessibility of reactants to the active catalyst surface to obtain maximum activity. For this optimum catalyst, the activation energy was evaluated to be 56.9 kJ mol−1. Although the catalyst was able to achieve almost the same conversion when the catalyst was repeatedly tested five times under the same condition, the catalytic activity decreased gradually. Overall, it could be revealed that Co-NPs supported on LDHs have a huge potential to be used for H2 energy production.

Sulphonated silica and sulphonated silica / carbon particles as efficient catalysts for hydrogen generation from sodium borohydride hydrolysis

In the present study, silica, sulphonated silica (SS) and sulphonated silica/carbon (SSC) particles are prepared by sol-gel method using tetra-ethyl ortho-silicate and glucose as sources for silica and carbon, respectively and used as catalysts for sodium borohydride (NaBH4) hydrolysis to produce hydrogen. The acid density calculated by back titration method shows the acidic nature of SS and SSC. Further, the catalysts are characterized using FT-IR, XRD, SEM, TEM, EDAX and N2 physisorption studies. TEM and N2 adsorption/desorption studies revealed the porous nature of the particles. Further, the catalytic activities of SS and SSC are analysed towards NaBH4 hydrolysis. It is found that both SS and SSC enhance the sodium borohydride hydrolysis significantly with hydrogen generation rates of 768 and 914 mL min−1 g−1, respectively. Using Arrhenius plot, the activation energies of SS and SSC are calculated as 24.74 and 18.97 kJ mol−1, respectively. Further, thermodynamic parameters like ΔH‡, ΔS‡ and ΔG‡ of the activated complex are calculated using Erying plot. The negative ΔS‡ value suggests that the mechanism of NaBH4 hydrolysis at SS and SSC follows Langmuir-Hinshelwood associative mechanism.

Electrosynthesis of Ni-Co/Hydroxyapatite as a Catalyst for Hydrogen Generation via the Hydrolysis of Aqueous Sodium Borohydride (NaBH4) Solutions

To generate hydrogen from its storage as NaBH4, a catalyst was synthesized via an electrochemical method. The catalyst, Ni-Co, had hydroxyapatite as a support catalyst. The electrochemical cell consisted of a DC power supply, a carbon anode and cathode, and a bipolar membrane to separate the cell into two chambers. The current density was adjusted to 61, 91, and 132 mA/cm2. The electrolysis time was 30, 60, and 90 min. The particles produced were analyzed by XRD and SEM/EDX and tested in the hydrolysis of NaBH4 for hydrogen generation. The Ni-Co/HA catalyst test concluded that the period of time used for electrolysis during catalyst formation was positively correlated with the rate of NaBH4 hydrolysis in the production of hydrogen. The highest rate of hydrogen production was obtained using the synthesized catalyst with a current density of 92 mA/cm2. The NaBH4 hydrolysis reaction followed a first-order reaction with the rate constant of (2.220–14.117)•10-3 l/(g•min). The Arrhenius equation for hydrolysis reactions within the temperature range of 300–323 K is k = 6.5•10-6exp(-6000/T).

Highly dispersed cobalt nanoparticles onto nitrogen-doped carbon nanosheets for efficient hydrogen generation via catalytic hydrolysis of sodium borohydride

Porous carbon nanostructures are promising supports for stabilizing the highly dispersed metal nanoparticles and facilitating the mass transfer during the reaction, which are critical to achieve the high efficiency of hydrogen generation from sodium borohydride dehydrogenation. Herein, the catalytically active porous architectures are simply prepared by using 2-methylimidazole and melamine as reactive sources. The structural and compositional characterizations reveal the coexistence of metallic cobalt and N-doped carbon in porous architectures. Electron microscopy observations indicate that the synthesized products are smartly constructed from the carbon nanosheets with densely dispersed Co nanoparticles. Due to the notable structural features, the prepared Co@NC-600 sample presents the highly efficient activity for catalytic hydrolysis of NaBH4 with a hydrogen generation rate of 2574 mL min−1 gcat−1 and an activation energy of 47.6 kJ mol−1. The catalytically active metallic Co and suitable support-effect of N-doped carbon are responsible for catalytic dehydrogenation.

The activity of ceria supported complex in hydrogen generation

In this study, we studied the ceria supported Ni complex preparation and using it as a catalyst in NaBH4 hydrolysis for H2 production. NaBH4 hydrolysis system was studied in different parameters, as concentration of Ni complex, concentration of NaBH4, concentration of NaOH, amount of catalyst and temperature. Additionally, catalyst was characterized by several analysis methods. Finally, the kinetic calculation of NaBH4 hydrolysis reaction was studied at 20 ℃-50 ℃ the activation energy was found to be 27.581 kJ/mol. The aim of this study is to emphasize that ceria support can be used to increase the catalyst surface and to obtain the high hydrogen generation activity through hydrolysis of NaBH4. The experimental results show that ceria supported Ni complex was an effective catalyst in hydrolysis of NaBH4.

Well‐Dispersed Ru‐Clusters Decorating Nanobox‐Structured CoP Synergistically Catalyze the NaBH4 Hydrolysis and Electro‐Reductive H2 Evolution

AbstractThe high‐efficiency multifunctional materials have considerable significance in the area of sustainable energy to developing a cross‐usable and low‐cost catalyst. Nevertheless, substantial challenges are ahead on designing and synthesizing a high performance in a scalable and straightforward manner. Here, we have developed a novel bifunctional catalyst based on Ru/CoP nanoboxes (NBs) prepared using ZIF‐67 as a precursor. The nano hollow box structure and the strong electronic interaction between Ru clusters and CoP component are confirmed. The Ru/CoP NBs as a catalyst show excellent activities for catalytic NaBH4 hydrolysis such as high turnover frequency (1202.2 min−1), and small electrocatalytic H2 evolution overpotential (49 mV@10 mA cm−2) under ambient conditions. Besides, Ru/CoP NBs also display good stability and reusability. The excellent catalytic performance of Ru/CoP NBs is attributed to the synergy between Ru clusters and CoP species as well as the unique morphology that accelerates charge transfer, provides higher active surface area, and facilitates solute transport and gas emission.

Superior hydrogen generation from sodium borohydride hydrolysis catalyzed by the bimetallic Co–Ru/C nanocomposite

Sodium borohydride has been widely regarded as a promising hydrogen carrier owing to its greatly hydrogen storing capability (10.8 wt%), high weight density and excellent stability in alkaline solutions. Herein, we first design and synthesize a series of bimetallic M-Ru/C nanocomposites (including Fe–Ru/C, Co–Ru/C, Ni–Ru/C and Cu–Ru/C), via simply alloying of commercial Ru/C with nonprecious metal, for superior H2 evolution from the NaBH4 hydrolysis. The result exhibits that H2 generation is synergetically improved by alloying Ru/C with Co or Ni, while it is hindered by alloying Ru/C with Fe or Cu. Indeed, Co–Ru/C presents the highest efficient catalytic activity for H2 generation, with the TOF of 117.69 mol(H2)·molRu−1·min−1, whereas Ru/C is only 57.08 mol(H2)·molRu−1·min−1. In addition, the TOF of Co–Ru/C reaches to 436.51 mol(H2)·molRu−1·min−1 (96.7 L(H2)·gRu−1·min−1) in the presence of NaOH.

Synthesis of Ni-B/Hydroxyapatite by Electrochemical Method and Its Application as Catalyst on NaBH<sub>4</sub> Hydrolysis

The result of burning hydrogen which is environmentally friendly makes hydrogen as a very attractive fuel. Hydrogen storage is interesting research material. One alternative to hydrogen storage is a metal-hydride as NaBH4. In this paper, the catalyst for hydrogen production from storage, namely The result of burning hydrogen, which is environmentally friendly, makes hydrogen a desirable fuel. Hydrogen storage is exciting research material. One alternative to hydrogen storage is a metal-hydride as NaBH4. In this paper, the catalyst for hydrogen production from storage, namely NaBH4, was synthesized by electrochemical. Ni-B catalyst with hydroxyapatite as catalyst support was prepared by electrochemical. Ni-B/HA catalyst was synthesized at various current densities (namely 67, 133, and 200 mA/cm2) and various electrolysis times (namely 30, 60, and 90 minutes). The resulting catalysts were analyzed by XRD and used as the catalyst for hydrogen production from the hydrolysis reaction of NaBH4. The fastest hydrogen production was obtained using a catalyst generated at 133 mA/cm2 and an electrolysis time of 60 minutes. The reaction rate equation for the hydrolysis of NaBH4 has a first-order reaction to the concentration of NaBH4. The resulting reaction rate constant ranged from 233.33 mL/g/min to 861.11 mL/g/min. The relationship between reaction temperature and reaction rate constant can be expressed by the equation k = 2.2x106exp (5534/T).

Rehydrogenation of Sodium Borates to Close the NaBH4-H2 Cycle: A Review

In 2007, the US Department of Energy recommended a no-go on NaBH4 hydrolysis for onboard applications; however, the concept of a NaBH4-H2-PEMFC system has the potential to become a primary source for on-demand power supply. Despite the many efforts to study this technology, most of the published papers focus on catalytic performance. Nevertheless, the development of a practical reaction system to close the NaBH4-H2 cycle remains a critical issue. Therefore, this work provides an overview of the research progress on the solutions for the by-product rehydrogenation leading to the regeneration of NaBH4 with economic potential. It is the first to compare and analyze the main types of processes to regenerate NaBH4: thermo-, mechano-, and electrochemical. Moreover, it considers the report by Demirci et al. on the main by-product of sodium borohydride hydrolysis. The published literature already reported efficient NaBH4 regeneration; however, the processes still need more improvements. Moreover, it is noteworthy that a transition to clean methods, through the years, was observed.

Enhanced reduction of bromate in water by 2-dimensional porous Co3O4 via catalytic hydrogenation

As catalytic hydrogenation is validated as one of the most useful approach to reduce a potential carcinogenic bromate in water, the usage of continuous purge H2 gas and precious metal catalysts are typically required, making it less feasible for practical implementation. Since sodium borohydride (NaBH4) represents a potential alternative source for releasing H2 and non-precious metal catalysts (cobalt (Co)) are usually required to accelerate the hydrolysis of NaBH4 for faster H2 production, the combination between Co-based catalysts and NaBH4 could be favorable for bromate hydrogenation. Especially, it is even more advantageous to fabricate a porous heterogeneous catalyst with high surface area. Thus, this study aims to construct such a novel porous heterogeneous catalyst for reducing bromate using sodium borohydride. Herein, a Co-coordinated framework with TMC ligand (CoTMC) is employed as precursor, which is then transformed into hexagonal porous Co3O4 (HPCO) via one-step calcination. The resultant HPCO possesses remarkable surficial oxygen vacancies as well as textural properties in comparison with Co3O4 NP. Importantly, HPCO could completely reduce bromate to bromide within 20 min. The calculated bromate removal capacity using HPCO and NaBH4 is achieved as 781.25 μmol/g, and the activation energy (Ea) is also calculated as 28.5 kJ/mol. Besides, HPCO also exhibits high catalytic activities for bromate reduction in the presence of various anions. Moreover, HPCO could be also reusable for reducing bromate to bromide over multiple-cycles without any remarkable change of catalytic activities. These features indicate that HPCO is a robust and effective heterogeneous catalyst for bromate reduction in water.

On-demand hydrogen evolution upon magnetic composite-nanocatalyzed sodium borohydride hydrolysis

Fast and convenient hydrogen evolution under ambient condition from stable hydrogen-rich materials is highly awaited. Herein, a series of magnetic nanocomposites are reported as robust catalysts for promoting H2 evolution upon hydrolysis of sodium borohydride. The optimized Ni2Rh-, Ni2Pd- and Ni2Pt/Fe3O4 nanocomposites exhibit outstanding catalytic performances on NaBH4 hydrolysis with remarkable TOF values of 72.2, 69.2 and 46.1 L(H2)·g.cat−1·min−1, respectively, due to sharp volcano-type synergetic effect between Ni and the noble metal. Based on the Arrhenius equation, the activation energy (Ea) of the hydrolysis of NaBH4 is 54.95 kJ/mol with the catalyst Ni2Pt/Fe3O4. The Ni2Pt/Fe3O4 has been successfully recycled 5 times and applied as an efficient “on–off” switch for on-demand H2 evolution.

Simple preparation of g-C3N4@Ni3C nanosheets and its application in supercapacitor electrode materials, hydrogengeneration via NaBH4 hydrolysis and reduction of p–nitrophenol

g-C3N4@Ni3C nano-sheets have been prepared by a simple pyrolysis under different temperature, and the as-prepared samples have been characterized by many means, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), the Brunauer–Emmett–Teller (BET) and pore size distribution. The as-prepared g-C3N4@Ni3C nano-sheet has been proved to be a versatile functional material, that is the application in supercapacitor electrode materials, hydrogen generation via NaBH4 hydrolysis and reduction of p–nitrophenol. This method offers a new strategy for preparation of environmental energy materials through simple raw materials.

Engineered nano-foam of tri-metallic (FeCuCo) oxide catalyst for enhanced hydrogen generation via NaBH4 hydrolysis

Catalytic hydrolysis of sodium borohydride can potentially be considered as a convenient and safe method to generate hydrogen, an environmentally clean and sustainable fuel for the future. The present effort establishes the development of FeCuCo tri-metallic oxide catalyst by a simple, single-step solution combustion synthesis (SCS) method for hydrogen generation from NaBH4 hydrolysis. Amongst series of FeCuCo tri-metallic oxide catalyst synthesized, FeCuCo with 50:37.5:12.5 wt% respective precursor loading displayed remarkable activity by generating hydrogen at the rate of 1380 mL min−1 g−1 (1242 mL in 18 min) with turnover frequency (TOF) of 62.02 mol g−1 min−1. The catalyst was characterized by using various techniques to understand their physiochemical and morphological properties. The results revealed that the catalyst synthesized by combustion method led to the formation of FeCuCo with appreciable surface area, porous foam-like morphology and high surface acidity. Major factors affecting the hydrolysis of NaBH4 such as catalyst loading, NaOH concentration and temperature variation were studied in detail. Additionally, the FeCuCo catalyst also displayed substantial recyclability performance up to eight cycles without considerable loss in its catalytic activity. Therefore, FeCuCo oxide can be demonstrated as one of the most efficient, cost effective tri-metallic catalyst so far for application in the hydrogen generation.

Co0.45W0.55 Nanocomposite from ZIF-67: An Efficient and Heterogeneous Catalyst for H2 Generation Upon NaBH4 Hydrolysis

Co0.45W0.55 Nanocomposite from ZIF-67: An Efficient and Heterogeneous Catalyst for H2 Generation Upon NaBH4 Hydrolysis

In situ transformation of 3D Co3O4 nanoparticles to 2D nanosheets with rich surface oxygen vacancies to boost hydrogen generation from NaBH4

Despite substantial progress in various application fields of polyoxometalates (POMs), the use of POMs as ligands to alter the structure of solid catalysts in heterogeneous catalysis requires additional efforts. Herein, we used the reduced α-SiW12O404- (RSTA) as an inorganic ligand to mediate Co3O4 nanoparticles that efficiently promote the hydrolysis of NaBH4 to generate hydrogen with multiple activities (4747 mL/(gcat·min)) compared with NaBH4-pretreated Co3O4 (1236 mL/(gcat·min)), pristine Co3O4 (inactive) and commercial Co3O4 (inactive) at 25℃. RSTA induced both electronic and morphology effects on Co3O4 through in situ driving 3D Co3O4 nanoparticles to 2D Co3O4 nanosheets with rich surface oxygen vacancies or Co2+ during the hydrolysis process. This modulation by RSTA allowed more active sites, including both electron-rich Co0 and electron-deficient Co2+, facilitating BH4- and H2O adsorption and thus hydrogen generation. The promoted mechanism of the RSTA on both the microstructure and the catalytic performance was further proposed.

Effects of accelerators, and metal salts on the hydrolysis of sodium tetrahydroborate: A kinetic and mechanistic study for hydrogen generation

Sodium tetrahydroborate (NaBH4) was used as a fuel source for hydrogen-oxygen fuel cell. The oxalic acid, Ag+, Cu2+ and Ni2+ accelerates the hydrogen (H2 gas) evolution from the self-hydrolysis of NaBH4 at 30 °C. Kinetics of H2 gas generation was evaluated as a function of catalyst, NaBH4, sodium hydroxide concentrations at different temperatures. Hydrolysis NaBH4 follows first-, and fractional-order kinetics with [BH4-], and [H+] respectively. The hydrolysis of NaBH4 decreases with increasing [NaOH] at 30 °C. The metal ions (Ag+, Cu2+, and Ni2+) catalyzed the evolution of H2 gas and hydrolysis followed zero-order kinetics with respect to the metal ions. Hydrolysis of NaBH4 was catalyzed by metal ions and hydrogen ions simultaneously. The activation parameters were calculated and found to be activation energy = 54.9, 59.7, 62.7 kJ/mol, enthalpy of activation = 52.4, 57.5, 60.2 kJ/mol and entropy of activation = −62.2, −48.2, −49.6 J/K/mol for Ag+, Cu2+ and Ni2+, respectively. The catalytic activity of depends on the reduction potential of metal ions; Ag+ (0.799 V) ˃ Cu2+ (0.341 V) ˃ Ni2+ (−0.257).

Synergistical photo-thermal-catalysis of Zn2GeO4:xFe3+ for H2 evolution in NaBH4 hydrolysis reaction

Herein, we reported the systematic investigation of synergistic photo-thermal-catalysis for NaBH4 hydrolysis reaction based on zinc orthogermanate. A series of Zn2GeO4:xFe3+ (x = 0 to 0.10) catalysts were prepared via solvothermal method. The H2 evolution experiments demonstrated that the photogenerated holes trap OH− not only shifted the equilibrium of NaBH4 hydrolysis reaction toward the direction of H2 evolution, but also inhibited the recombination of photogenerated carriers. With the remarkable photo-thermal synergism for the as-prepared catalysts, the H2 evolution rate in photo-thermal-driven condition had witnessed several times higher than that in mono-energy driven condition. The catalysts remained stable after circulation tests.

Preparation of CoB nanoparticles decorated PANI nanotubes as catalysts for hydrogen generation from NaBH4 hydrolysis

Magnetic agglomeration of CoB nanoparticles in the hydrogen production from the hydrolysis of NaBH4 aqueous solution always degrades their catalytic activity. This work aims at the rational development of robust supported CoB catalyst that is active and stable towards NaBH4 hydrolysis. In this study, PANI nanotubes derived from PS nanofiber templates are firstly synthesized by the polymerization of aniline followed by the template removal. CoB nanoparticles are then decorated into PANI nanotubes via an impregnation and chemical reduction method. It can be found that CoB nanoparticles can be confined into the internal surface of PANI nanotubes which improves the dispersion and anchored stability of CoB nanoparticles. The as-prepared CoB/PANI composite catalyst exhibits a high catalytic performance and recycling stability. The hydrogen production rate as high as 2300 ml. min−1. g − 1 is achieved and the activation energy was calculated to be only 37.75 kJ/mol. Meanwhile, CoB/PANI catalyst displays excellent stability in NaBH4 hydrolysis during five cycles. The experimental results indicated that as-synthesized CoB/PANI composite catalysts are very efficient towards hydrogen production from NaBH4 hydrolysis.