Catalytic Hydrolysis Of NaBH4 Research Articles

Hydrogen evolution from NaBH4 solution using Cr-doped Ni–B metallic catalyst deposited on rice husk via electroless plating

Hydrogen evolution through the catalytic hydrolysis of NaBH4 by transition metals holds great promise for sustainable green energy production. In this study, we presented an electroless process for synthesizing Cr-doped Ni–B catalysts supported on rice husks. The kinetics and thermodynamics of the NaBH4 hydrolysis were systematically investigated. The crystallography confirmed the formation of Ni and Cr connected to B. 0.8 wt% Cr also significantly impacted the Ni–B activity and enhanced the hydrogen generation rate from 394 to 801 ml min−1.g−1 at 32 °C. Based on Kinetics, NaBH4 hydrolysis by Ni–B–Cr0.8 needs an activation energy of 50.64 kJ mol−1 and follows zero- and first-order kinetics concerning NaBH4 and catalyst weight. After five cycles reusability, the Ni–B–Cr0.8 revealed excellent stability and kept its activity almost constant in basic NaBH4 solution.

Catalytic hydrolysis of NaBH4 over titanate nanotube supported Co for hydrogen production

A Co/HTNT catalyst is developed by immobilizing Co on the surface of titanate nanotubes. The microstructure and composition of the catalyst are investigated with atomic absorption spectroscopy (AAS), high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), Fourier transform infrared spectrometer (FT-IR) and X-ray photoelectron spectroscopy (XPS). The developed Co/HTNT catalyst shows great performance in catalyzing NaBH4 hydrolysis. The hydrolysis of 25 mg NaBH4 catalyzed by 50 mg Co/HTNT in 10 g NaOH solution (12.5 wt%) provides a hydrogen production rate of 1.04 L min−1 gCo−1 at 30 °C, and the activation energy of the reaction is 29.68 kJ mol−1. The high catalytic activity and economical property make this catalyst a promising choice for on-site hydrogen production from NaBH4 hydrolysis.

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.

Optimization of Hydrogen Generation by Catalytic Hydrolysis of NaBH4 with Halloysite-Supported CoB Catalyst Using Response Surface Methodology

AbstractThe hydrolysis of sodium borohydride (NaBH4) is a promising reaction with a possible practical application as a means of generating hydrogen. The efficiency of hydrogen production can be enhanced significantly by use of a catalyst during the reaction. Cobalt borides show significant catalytic activity, but unsupported CoB particles aggregate easily and are difficult to separate from the reaction medium for re-use. The objectives of the present study were to use halloysite (Hly) as a support material to increase the catalytic activity and reusability of a Co metal-based system and to investigate the binary effect of metal loading and reaction parameters on the hydrolysis of NaBH4. Catalysts were prepared by wet impregnation and chemical reduction. The surface morphology and structural properties of the prepared catalysts were characterized using N2 adsorption-desorption and the Brunauer-Emmet-Teller (BET) method, field emission scanning electron microscopy (FE-SEM), with energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and inductively coupled plasma mass spectrometry (ICP-MS). Response surface methodology (RSM) was used to optimize metal loading and reaction conditions for the hydrogen-generation rate. Optimum reaction conditions were determined (using Design Expert 7.0 software) as 5.01 wt.% Co loading using a Co-B/Hly-supported catalyst, 0.44 M NaBH4, 10.66 mg catalyst, and at a reaction temperature of 39.96°C. The maximum hydrogen generation rate was 33,854 mL min−1 gCo−1 under these conditions.

Cobalt oxide supported multi wall carbon nanotube catalysts for hydrogen production via sodium borohydride hydrolysis

Cobalt oxide supported multi-wall carbon nanotubes (Co/MWCNTs) catalysts with different cobalt oxide loadings were synthesized by simple impregnation method. The synthesized Co/MWCNTs materials were used as catalysts for hydrolysis of sodium borohydride (NaBH4), an effective route to produce clean hydrogen. The effect of some parameters such as Co loading, reaction temperature and reaction time were investigated on the performance of catalysts in hydrolysis of NaBH4. The hydrogen generation rate was found to be 409 mLg−1min−1 at 35 °C for Co/MWCNTs-20 catalyst in NaBH4 hydrolysis, while it is 28 mLg−1min−1 for bulk MWCNTs support. The physico-chemical characteristics such as crystalline phase, morphology, particle size, reducibility, surface and textural properties of the catalysts were studied by using powder XRD, FE-SEM, TEM, N2-physorption, XPS and H2-TPR techniques. The reduction temperature of cobalt oxide species was shifted to lower temperatures after impregnation of nanosized Co oxides on the MWCNTs support. It was also observed that presence of more number of surface Co2+ species in Co/MWCNTs-20 catalyst is responsible for superior activity in catalytic hydrolysis of NaBH4. The obtained results also suggested that Co/MWCNTs catalysts can be reused for five cycles with a slight loss of activity.

Cotton stalk activated carbon-supported Co–Ce–B nanoparticles as efficient catalysts for hydrogen generation through hydrolysis of sodium borohydride

Porous cotton stalk activated carbons (CSAC) were prepared by phosphoric acid activation of cotton stalks in a fluidized bed. The CSAC-supported Co–B and Co–Ce–B catalysts were prepared by the impregnation-chemical reduction method. The samples were characterized by the nitrogen adsorption, XRD, FTIR and TEM measurements. The effects of the sodium borohydride (NaBH4) and sodium hydroxide (NaOH) concentrations, reaction temperature and recyclability on the rate of NaBH4 hydrolysis over the CSAC-supported Co–Ce–B catalysts were systematically investigated. The results showed that the agglomeration of the Co–Ce–B nanoclusters on the CSAC support surface was significantly reduced with the introduction of cerium. The CSAC-supported Co–Ce–B catalyst exhibited superior catalytic activity and the average hydrogen generation rate was 16.42 L min−1 g−1Co at 25 °C, which is higher than the most reported cobalt-based catalysts. The catalytic hydrolysis of NaBH4 was zero order with respect to the NaBH4 concentration, and the hydrogen generation rate decreased with the increase in the NaOH concentration. The activation energy of the hydrogen generation reaction on the prepared catalyst was estimated to be 48.22 kJ mol−1. A kinetic rate equation was also proposed.

Sustainable Hydrogen Generation by Catalytic Hydrolysis of NaBH4 Using Tailored Nanostructured Urchin-like CuCo2O4 Spinel Catalyst

The present study describes the hydrogen production as a future energy source via hydrolysis of NaBH4 catalyzed by urchin-like CuCo2O4 spinel catalyst prepared by urea-assisted hydrothermal synthesis method. The as-synthesized copper–cobalt double hydroxide precursor and the resultant CuCo2O4 spinel were characterized by using various analytical, spectroscopic and microscopic techniques in order to understand their physiochemical and morphological aspects. The detail characterization results confirmed the successful formation of CuCo2O4 spinel phase with urchin-like morphology. The CuCo2O4 spinel catalyst was then tested for its application in hydrogen generation from NaBH4 hydrolysis by performing the reaction using 10 wt% of CuCo2O4 spinel catalyst and 0.5 g NaBH4 at room temperature. The CuCo2O4 spinel catalyst with tailored architecture displayed high catalytic activity with H2 generation rate of 1370 mL min−1 g−1 (1438 mL in 21 min). Major factors affecting the hydrolysis of NaBH4 reaction such as catalyst loading, NaOH concentration and temperature variation was also studied and discussed in detail. Correspondingly, the low activation energy of 22 kJ mol−1 was obtained from the Arrhenius plot and kinetic studies revealed that the hydrolysis of NaBH4 followed first order kinetics. Further, recyclability study of CuCo2O4 spinel catalyst was also performed which displayed good catalytic activity and stability even after five successive recycles. Characterization data of reused catalyst revealed that physiochemical properties of fresh CuCo2O4 spinel catalyst were well-preserved in the reused catalyst as well. Therefore, nanostructured CuCo2O4 spinel can be demonstrated as one of the most efficient, cost effective bimetallic spinel catalyst so far for application in the hydrogen generation.

Alloyed zeolite catalyst component, method for making and catalytic application thereof

Porous cotton stalk activated carbons (CSAC) were prepared by phosphoric acid activation of cotton stalks in a fluidized bed. The CSAC-supported Co–B and Co–Ce–B catalysts were prepared by the impregnation-chemical reduction method. The samples were characterized by the nitrogen adsorption, XRD, FTIR and TEM measurements. The effects of the sodium borohydride (NaBH4) and sodium hydroxide (NaOH) concentrations, reaction temperature and recyclability on the rate of NaBH4 hydrolysis over the CSAC-supported Co–Ce–B catalysts were systematically investigated. The results showed that the agglomeration of the Co–Ce–B nanoclusters on the CSAC support surface was significantly reduced with the introduction of cerium. The CSAC-supported Co–Ce–B catalyst exhibited superior catalytic activity and the average hydrogen generation rate was 16.42 L min−1 g−1Co at 25 °C, which is higher than the most reported cobalt-based catalysts. The catalytic hydrolysis of NaBH4 was zero order with respect to the NaBH4 concentration, and the hydrogen generation rate decreased with the increase in the NaOH concentration. The activation energy of the hydrogen generation reaction on the prepared catalyst was estimated to be 48.22 kJ mol−1. A kinetic rate equation was also proposed.

Hydrogen production through the cooperation of a catalyst synthesized in ethanol medium and the effect of the plasma

ABSTRACT In the present study, nanostructured Ni-B catalysts were successfully prepared in ethanol medium using the chemical reduction method for hydrogen production from the catalytic hydrolysis of sodium borohydride (NaBH4). Ni-B nanostructures were characterized by several analysis methods including XRD, SEM/EDS, FT-IR and BET. The effects of factors such as solution temperature, NaBH4 loadings, catalyst amount and NaOH concentration on the performance of these catalysts in the production of hydrogen from alkaline NaBH4 solutions were investigated in detail. In addition, the Ni-B catalyst prepared in ethanol medium and subjected to plasma for the hydrogen production from the catalytic hydrolysis of NaBH4 was investigated. The Ni-B catalyst prepared in ethanol medium showed maximum hydrogen production rate (1000 mL min−1gcatalyst−1) which was approximately 2 times higher than the rate obtained from the Ni-B catalyst prepared in water (400 mL min−1gcatalyst−1) and acethone (550 mL min−1gcatalyst−1). The Ni-B nanoparticles showed the best catalytic activity at 333 K with a maximum hydrogen production rate of 7134 mL min−1gcatalyst−1 and activation energy of 46.83 kJmol−1 for the NaBH4 hydrolysis reaction in the Ni-B catalysts prepared in ethanol and subjected to plasma. As the Ni-B catalyst is inexpensive and easy to prepare, it is feasible to use this catalyst in the construction of practical fuel cells for portable and in situ applications.

Magnetic CoOx@C-Reduced graphene oxide composite with catalytic activity towards hydrogen generation

Cobalt-containing magnetic core-shell structures are alternative catalysts with better catalytic performance for hydrogen evolution. In this study, a facile route is adopted to fabricate a CoOx@carbon-reduced graphene oxide composite containing Co nanoparticle cores, carbon shells, and reduced graphene oxide. During hydrogen generation through the catalytic hydrolysis of NaBH4 and NH3BH3, the surface of CoOx cores provides active catalytic sites, and the carbon shells protect the CoOx cores from aggregating into gigantic cobalt oxide granules. The magnetism of CoOx anchored onto reduced graphene oxide sheets achieves effectively a momentum transfer assisted by a motional external magnetic field. In a batch reactor, the composite exhibits a higher catalytic activity in a self-stirring mode than that in a magneton-stirring mode. This simple and efficient synthesis strategy is highly promising for the next development of both facile hydrogen generation and core-shell composite functional materials.

Hydrogen evolution from catalytic hydrolysis of NaBH4: Comparative study between the catalytic activity of TiO2 nanotubes with various arrangements

Nowadays, a lot of efforts have been applied to find an appropriate catalyst for generating hydrogen from NaBH4. Hence in the current study, various nanostructures of TiO2 were employed to obtain an insight into how the different support catalysts effect on the hydrolysis rate of NaBH4. For this aim, disordered filaments (DF-NTs) and ordered free-standing TiO2 nanotubes (FS-NTs) were fabricated via hydrothermal and chemical-assisted two-step anodization methods, respectively. The physical and chemical features of catalysts were analyzed using FESEM, XRD, FTIR and BET analysis, respectively. The results showed, TiO2 itself has catalytic activity and the H2 generation rate by FS-NTs was 1.67 and 5.26 times more than the generation rate by DF-NTs and spherical TiO2 nanoparticles, respectively. This premier catalytic behavior of FS-NTs can be ascribed to its high surface area (112.77 m2/g) and ordered arrangement of the nanotubes which allows reagents to be easily transferred to the active sites. The kinetic study revealed that hydrolysis of NaBH4 using the catalyst of FS-TNs is a first-order reaction regarding catalyst amount, while it is a zero-order reaction regarding the NaBH4 level. Moreover, the reusability results exhibited that FS-TNs has good durability and performance even up to the Fifth run.

Investigation of High-Activity Activated Carbon-Supported Co-Cr-B Catalyst in the Generation of Hydrogen from Hydrolysis of Sodium Borohydride

In this study, activated carbon-supported Co-Cr-B catalyst was synthesized by chemical impregnation and precipitation method for use in the catalytic hydrolysis of sodium borohydride (NaBH4). The activity of Co-Cr-B / activated carbon (5-20%) obtained by using different ratios was investigated while synthesizing activated carbon-supported Co-Cr-B catalyst. The effects of some parameters such as NaOH Concentration (0-5%), NaBH4 concentration (2.5-10%), amount of catalyst (25-100 mg) and solution ambient temperature were investigated in the catalytic hydrolysis of NaBH4. The hydrogen production rate of Co-Cr-B catalyst without support in hydrolysis of NaBH4 was found as 6.5 Lg-1 min-1 catalyst while the hydrogen production rate of activated carbon supported Co-Cr-B catalyst was found as 30.2 Lg-1 min-1 catalyst. In presence of activated carbon-supported Co-Cr-B catalyst, the hdyrolysis kinetic order and activation energy of NaBH4 were found as 0.126 and 16.27 kJ/mol, respectively. The results suggest that activated carbon-supported Co-Cr-B catalysts can be used for mobile applications of Proton exchange membrane fuel cell (PEMFCs) systems.

Hydrogen generation as a clean energy through hydrolysis of sodium borohydride over Cu-Fe-B nano powders: Effect of polymers and surfactants

The aim of this study is to prepare Cu-Fe-B catalysts with different Cu:Fe molar ratios under ultrasonic conditions. The catalytic activity of all catalysts is tested for hydrogen generation through hydrolysis of alkaline sodium borohydride solution. The effect of polymers (PEG and PVP) and surfactants (CTAB, SDS and Triton X-100) as stabilizer agents on size, morphology and catalytic activity was studied. XRD, TEM, FE-SEM, ICP-OES and BET techniques have been employed for the characterization of catalysts. The TEM image depicts that PEG-stabilized Cu:Fe (3:1) catalyst is a flaky shaped particle containing many nanosheets. The various morphologies of Cu-Fe-B nano catalysts were also confirmed by FE-SEM images. It can be found that PEG and PVP resulted in puffy and nanoparticle shapes, respectively. FE-SEM images of surfactants stabilized Cu-Fe-B powders, CTAB, SDS and Triton X-100, show platy form and agglomerated particles. The PEG-stabilized Cu-Fe-B catalyst with a Cu: Fe molar ratio of 3:1 shows the best catalytic activity at 318 K. In addition, the effects of the concentration of NaBH4, NaOH and the reaction temperature on catalytic activity of Cu-Fe-B have been studied for the hydrogen generation rate. The results of the kinetic study show that the catalytic hydrolysis of NaBH4 is first order with respect to the catalyst dosage and is also first order with respect to the NaBH4 concentration. The activation energy of the hydrolysis for PEG-stabilized Cu-Fe (3:1) catalysts is calculated as 57 kJ mol−1. The results of reusability tests show that PEG-stabilized Cu-Fe (3:1) catalyst is active even up to the third run.

In situ synthesis of cobalt-based tri-metallic nanosheets as highly efficient catalysts for sodium borohydride hydrolysis

The well dispersed magnetically recyclable tri-metallic nanosheets with non-noble metallic elements have been successfully synthesized via a facile one-step in situ procedure using sodium borohydride (NaBH4) as the reducing agent. The 2-D metal nanosheets exhibit higher catalytic activities for hydrolytic dehydrogenation of NaBH4 than those traditional mono-metallic, bimetallic and trimetallic alloy nanoparticles. The synergetic interaction between Co and Ni in CuCoNi nanosheets may play a critical role in the enhanced catalytic activity. Furthermore, the kinetic studies indicate that the catalytic hydrolysis of NaBH4 by the CuCoNi nanosheets is first order, with the activation energy measured to be 40.6 kJ mol−1.

Bimetallic Co–Ni based complex catalyst for hydrogen production by catalytic hydrolysis of sodium borohydride with an alternative approach

Hydrogen is a clean energy carrier and is expected to be one of the main energy sources in the 21st century. The basic aim of this study is to develop a feasible new catalyst system for the hydrogen generation by catalytic hydrolysis of NaBH4. The method is an alternative approach for the hydrogen production with metal catalysts. Ni–Co bimetallic complex catalysts with different Co–Ni contents were derived from 4-4′-methylene bis (2,6-diethyl)aniline-3,5-di-tert-butylsalisilaldimin ligand and their catalytic performances were investigated with hydrogen generation by catalytic hydrolysis of NaBH4. Experimental results showed that the Co–Ni contained catalysts exhibited much higher activity than the monometallic complex catalyst. The optimal mixture percentage of Co–Ni complex catalyst was 80:20. It was found that a combination of 2.5 wt% NaBH4 solution concentration and 5 wt% NaOH yields the highest performance for the hydrogen generation. The catalysts were characterized by XRD, FT-IR and SEM techniques.

Reduction of cobalt ion improved by lanthanum and zirconium as a triphenylphosphine stabilized nano catalyst for hydrolysis of sodium borohydride

La–Zr co-doped Co–B nanoparticle stabilized by Triphenylphosphine (TPP) is for the first time prepared in situ reduction by sodium borohydride at reflux condition. Obtained powders were characterized by XRD, BET, ICP, SEM–EDS and TEM techniques. TEM images depict that Co–B is appears formless and agglomerated powder. There are no agglomerated TPP stabilized La–Zr co-doped Co–B nanoparticles. It is concluded that, TPP as stabilizing agent can prevent agglomeration. TPP stabilized nanoparticle is formed as a spherical shaped particle. Particle size distribution is prepared and average size particle is about 13 nm. TPP stabilized La–Zr co-doped Co–B nanoparticle is highly active catalyst for hydrogen generation through the hydrolysis of sodium borohydride. It is also includes the full experimental details for the collection of a wealth of kinetic data to determine the activation energy (Ea = 45 kJ mol−1). Catalytic hydrolysis of NaBH4 is first order with respect to the catalyst concentration and also first order to the NaBH4 concentration in the case of TPP stabilized La–Zr co-doped Co–B nanoparticles.

Hydrogen Production by Catalytic Hydrolysis of Sodium Borohydride with a Bimetallic Solid-State Co-Fe Complex Catalyst

The addition of the active non-noble metal species on a ligand can influence the catalytic performance of catalyst. In the present work, a new bi-metallic solid-state complex catalyst system, including 4-4’-methylene bis(2,6-diethyl) aniline-3,5-di-tert-butylsalisilaldimin ligand and Fe and Co metal salts are prepared for hydrogen generation by catalytic hydrolysis of NaBH4. It was found that the Co/Fe mixture ratio, temperature, NaBH4, and NaOH concentrations, all exert considerable influence on the catalytic effectiveness of Co–Fe complex catalyst towards the hydrolysis reaction of NaBH4. The results suggested that the optimal mixture percentage of Co–Fe complex catalyst is 80:20. The obtained complex catalysts are characterized by XRD, FT-IR, and SEM techniques.

Hydrogen production through hydrolysis of sodium borohydride: Oleic acid stabilized Co–La–Zr–B nanoparticle as a novel catalyst

OL (Oleic acid)–Cobalt–Lanthanum–Zirconium–Boron nanoparticle was synthesized by chemical reduction of chloride salts of metals in the presence of oleic acid as stabilizing agent. The obtained materials were characterized by XRD (X-ray diffraction), TEM (Transmission electron microscopy), ICP-OES (Inductively Coupled Plasma Optical Emission Spectroscopy), BET (Brunauer–Emmett–Teller) and UV–vis (Ultraviolet–visible) techniques. XRD pattern declares that under Argon atmosphere only metal boride phase has been crystallized and it is not seen any oxide phase of metals. TEM image depicts there are not form any agglomerated nanoparticle. Particle size distribution was prepared and average size particle is about 25 nm. OL stabilized Co–La–Zr–B nanoparticle is active for hydrogen generation from the hydrolysis of sodium borohydride. The reported work also includes the full experimental details for the collection of a wealth of kinetic data to determine the activation energy (Ea = 51.24 kJ mol−1) and effects of the catalyst dosage, amount of substrate, and temperature on the rate for the catalytic hydrolysis of sodium borohydride. Catalytic hydrolysis of NaBH4 is first order with respect to the catalyst concentration and also first order to the NaBH4 concentration in the case of OL stabilized Co–La–Zr–B nanoparticles.

Hydrogen generation from hydrolysis of sodium borohydride by cubic Co–La–Zr–B nano particles as novel catalyst

Cubic Co–La–Zr–B nano particles were prepared in situ for the first time from the reduction of Co(II), La(III) and Zr(IV) chloride by sodium borohydride in methanol under reflux condition. Poly N-vinyl-2-pyrrolidone (PVP) as stabilizing agent was used for preparation of Co–La–Zr–B nano particles. Obtained powders were characterized by XRD, BET, ICP, SEM, TEM and UV–vis techniques. XRD patterns declare that under argon atmosphere only metalboride phase has been crystallized and it was not seen any oxide phase of metals. TEM image depicts that PVP stabilized nano particles are square shaped particles that containing many nanoclusters. Cubic Co–La–Zr–B nano particles were also confirmed by SEM image. Co–La–Zr–B is highly active catalysts for hydrogen generation from the hydrolysis of sodium borohydride. The reported work also includes the full experimental details for the collection of a wealth of kinetic data to determine the activation energy (Ea = 53 kJ mol−1) and effects of the catalyst dosage, amount of NaBH4, and temperature on the rate of the catalytic hydrolysis of sodium borohydride. Catalytic hydrolysis of NaBH4 is first order with respect to the catalyst concentration and also first order to the NaBH4 concentration in the case of cubic Co–La–Zr–B nano particles.

Synthesis and characterization of Co–La–Zr–B quaternary amorphous nano alloy: Kinetic study for hydrogen generation from hydrolysis of sodium borohydride

Abstract Co–La–Zr–B quaternary amorphous nano alloy was for the first time prepared in situ ultrasound-assisted reduction of Co(II), La(III) and Zr(IV) chloride by sodium borohydride aqueous solution. Obtained powder was characterized by XRD, BET, ICP, FE-SEM and TEM techniques. No distinct peak could be observed in XRD pattern of the obtained alloy indicating that the Co–La–Zr–B possessed amorphous structure. Regarding to the size, SEM and TEM images depict that the most of particles are lower than 10 nm and there is no significant aggregation. Co–La–Zr–B nano alloy is highly active catalysts for hydrogen generation from the hydrolysis of sodium borohydride. The reported work also includes the full experimental details for the collection of a wealth of kinetic data to determine the activation energy ( E a = 60.06 kJ mol −1 ) and effects of the catalyst dosage, amount of substrate, and temperature on the rate for the catalytic hydrolysis of sodium borohydride. Catalytic hydrolysis of NaBH 4 is first order with respect to the catalyst concentration and zero order respect to the NaBH 4 concentration in the case of Co–La–Zr–B quaternary amorphous nano alloy.