NaBH4 Hydrolysis Research Articles

EFFECTIVE POLYMER DECORATION ON NICKEL-IMINE COMPLEX TO ENHANCE CATALYTIC HYDROGEN EVOLUTION

Since fossil fuels are rapidly depleting, finding alternative energy sources is becoming increasingly important. Among these alternatives, hydrogen (H2) is the most viable option. In hydrogen evolution systems, supported metal catalysts enhance the catalytic activity in the hydrolysis reaction by increasing the surface area. Therefore, this research focuses on preparing three different polymer-decorated Nickel-Imine complex catalysts (Ni@EC, Ni@EC-250, Ni@ECM) to improve their efficiency. To achieve the catalysts, a Nickel-Imine complex [1] was supported on three different polymers (EC, EC-250, and ECM). The catalysts (Ni@EC, Ni@EC-250, Ni@ECM) were then utilized to generate hydrogen from NaBH4 hydrolysis. The hydrogen evolution rates for Ni@EC, Ni@EC-250, and Ni@ECM catalysts were found as 6879; 15576; 8830 and 15459; 28689; 23417 mL H2 gcat-1.min-1, respectively at 30 oC and 50 oC. Results indicate that the Ni@EC-250 catalyst exhibited the best activity. Consequently, the subsequent steps of the catalytic hydrolysis reaction were studied using Ni@EC-250. The activation energy of the Ni@EC-250 catalyst was estimated at 39.255 kJ.mol-1. The reusability tests demonstrate that Ni@EC-250 remains active in sodium borohydride hydrolysis even after five runs. Technical abbreviations are defined upon first use. This study elucidates the reaction mechanism and kinetic data of catalytic sodium borohydride hydrolysis at various temperatures.

“Click” Chemistry Assisted Synthesis of Magnetite‐CNT Nanohybrid Supported Gold Nanoparticles for Enhanced Catalytic Reduction of 4‐Nitrophenol

AbstractThe magnetite (Fe3O4) nanoparticles were strategically tethered over carbon nanotube (CNT) templates by using UV light‐induced thiol‐yne “click” chemistry approach which was followed by immobilization of chitosan stabilized gold nanoparticles (Au NPs) onto this surface through electrostatic interactions. Their application as a magnetically recyclable catalyst was explored through the study of the model catalytic reaction of reduction of 4‐nitrophenol (4‐NP) in the presence of an excess of NaBH4. Kinetic studies on the reduction of 4‐nitrophenol revealed Au/Fe3O4−CNT ternary nanohybrids to serve as better catalytic systems compared to Au NPs. The catalytic reduction of 4‐NP was found to occur through the formation of active gold hydride (Au−H) species. The formation of Au−H species was facilitated by Au−Fe3O4 interaction through the transfer of hydride ions via dissociation of the B−H bond of the adsorbed borohydride ions [BH4]− and the heterolytic dissociation of molecular hydrogen (H2), produced on hydrolysis of NaBH4 on the surface of Au/Fe3O4. Moreover, the π–π interactions between the nitroaromatic ring of 4‐NP and the CNT surface are believed to facilitate their proximity. Further, on visible light irradiation, dissociation of H2 on the gold surfaces was enhanced by the localized surface plasmon resonance (LSPR)‐induced hot electrons.

MOF‐Templated Hierarchical Porous Hollow Core‐Shell Framework Cobalt Oxide for Enhancing Hydrogen Generation from Borohydride‐Based Hydrolysis

AbstractDesigning and fabricating a competent cobalt‐based catalyst for sodium borohydride (NaBH4) hydrolysis is of great importance. The present work reports the synthesis of hierarchical porous hollow core‐shell framework cobalt oxide (HCSCO) via etching and calcination processes, which is then employed for catalyzing NaBH4 hydrolysis. The surface morphology and the hollow core‐shell framework of HCSCO were revealed by scanning electron microscope (SEM) and transmission electron microscope (TEM) analyses; the crystalline structure and the formation of Co3O4 in HCSCO were determined by X‐ray diffraction (XRD) and Raman spectroscopy; the surface area and porosity of HCSCO were verified by N2 adsorption‐desorption isotherm; and X‐ray photoelectron spectroscopy (XPS) was utilized to examine the chemical states of HCSCO. The as‐prepared HCSCO showed prominent catalytic hydrolysis of NaBH4 to generate H2 with a H2 generation rate of 441 ml min−1 gcatalyst−1 and a low activation energy (Ea) of 34.8 kJ mol−1. This Ea value of HCSCO is substantially lower than that of other catalysts, including noble metal catalysts or composites reported in the literature. Besides, HCSCO could remain its superb activity (~100 % H2 generation efficiency) over multiple hydrolysis cycles without significant changes of morphology and microstructure. The catalytic hydrolysis mechanism for H2 generation from NaBH4 using HCSCO is also proposed. This work provides a valuable strategy for the synthesis and fabrication of state‐of‐art catalysts for H2 generation from the hydrolysis of NaBH4.

Co@SiO2/C catalyst shielded by hierarchical shell for robust hydrogen production

NaBH4 hydrolysis under mild conditions is a promising solution for mobile hydrogen applications. However, the design and synthesis of cost-effective catalysts with sufficiently high activity and stability remain challenging. Herein, we report a facile approach to construct a series of SiO2 shielding cobalt-based catalysts with hierarchical active sites. Under optimized conditions, the hydrogen productivity of 18% Co@SiO2/C-300 is 8-fold higher than 18% Co/C catalyst without SiO2 shell. The incorporation of SiO2 shell enhances the partial oxidation of Co nanoparticles, resulting in the formation of a mesosphere CoOx overlayer covered by a SiO2 shell on Co particles. Meanwhile, the cobalt oxide on Co NPs could remain stable under reductive reaction conditions. The unique structural and electronic properties of the Co@SiO2/C configuration is demonstrated to enhance the activation of NaBH4 and H2O and promote H2 desorption, giving rise to a higher level of inherent activity and a relatively low reaction energy barrier.

Graphene Oxide from Graphite of Spent Batteries as Support of Nanocatalysts for Fuel Hydrogen Production

The increasing production of electronic waste and the rising demand for renewable energy are currently subjects of debate. Sustainable processes based on a circular economy are required. Then, electronic devices could be the main source for the synthesis of new materials. Thus, this work aimed to synthesize graphene oxide (GO) from graphite rod of spent Zn-C batteries. This was used as support for Ni/Co bimetallic nanocatalysts in the evolution of hydrogen from NaBH4 for the first time. The graphene oxide (GO) exhibited a diffraction peak at 2θ = 9.1°, as observed using X-ray diffraction (XRD), along with the presence of oxygenated groups as identified using FTIR. Characteristic bands at 1345 and 1574 cm−1 were observed using Raman spectroscopy. A leaf-shaped morphology was observed using SEM. GO sheets was observed using TEM, with an interplanar distance of 0.680 nm. Ni/Co nanoparticles, with an approximate size of 2 nm, were observed after deposition on GO. The material was used in the evolution of hydrogen from NaBH4, obtaining an efficiency close to 90%, with a kinetic constant of 0.0230 s−1 at 296.15 K and activation energy of 46.7 kJ mol−1. The material showed an efficiency in seven reuse cycles. Therefore, a route of a new material with added value from electronic waste was obtained from an eco-friendly process, which can be used in NaBH4 hydrolysis.

Optimizing Co2+ concentration on high-index Co3O4 facets enhances the catalytic performance in NaBH4 hydrolysis

Hydrogen is a viable alternative to fossil fuels due to its clean-burning properties and high energy density. However, a key challenge lies in the environmentally friendly production and storage of H2. NaBH4 could provide a solution by efficiently storing and releasing H2 through hydrolysis. Current catalysts for NaBH4 hydrolysis often contain cobalt (Co) and precious metals, raising concerns about their environmental impact and cost. To address this, this work proposes the development of efficient Co-only catalysts. Specifically, we explore the role of different crystal facets, specifically (311) and (220), in Co3O4 nanoparticles, demonstrating that an elevated CoO concentration in the (220) facet results in better catalysis for NaBH4 hydrolysis compared to traditional Co/precious metal composites. This improved catalyst shows promise for sustained use and minimal loss of catalytic activity, making it a potential solution for clean H2 production. Additionally, the findings may have broader applications in electrocatalysis and photocatalysis.

High-efficient treatment of 4-nitrophenol wastewater in an upflow bubbling fluidized bed reactor based on Pickering emulsion

The Pickering emulsion continuous flow catalytic system is widely applied in chemical synthesis and catalytic reaction. However, the traditional system generally adopts top feeding method resulting in the tight bed, which greatly limits the flow and transport of reactant. Herein, a upflow bubbling fluidized bed reactor based on Pickering emulsion is successfully constructed to the treatment of 4-nitrophenol wastewater. Here, the stable and efficient O/W Pickering emulsion in the bed reactor benefits from the preparation of an emulsifier with highly active interfacial catalyst (Pd@SiO2). The flow configuration from bottom to top and H2 bubbles from the hydrolysis of NaBH4 can produce the obvious looseness of bed with Pickering emulsion in the continuous flow system, improving the flow and transport of reactant to catalyst surface and the reaction performance. Under the condition of low catalyst loading (0.2 wt%), the conversion of high concentration 4-NP (1 mM) wastewater remains more than 98.5 % for 60 h constantly, demonstrating the excellent catalytic efficiency of the bubbling fluidized bed reactor. Results show that a continuous flow catalytic system with the new flow configuration yields outstanding performance for wastewater treatment.

Hydrogen Generation from NaBH4 Hydrolysis Catalyzed with Efficient and Durable Ni–Co Bimetal Catalyst Supported by ZIF-67/rGO

Hydrogen Generation from NaBH4 Hydrolysis Catalyzed with Efficient and Durable Ni–Co Bimetal Catalyst Supported by ZIF-67/rGO

Potential of nickel oxide catalyst from banana peel extract via green synthesis method in both photocatalytic reduction of methylene blue and generation of hydrogen from sodium borohydride hydrolysis

In the present work, nickel oxide (NiO) catalyst was prepared using banana peel extract as a stabilizing agent via the green synthesis method. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDX), X-ray diffraction (XRD), transmission electron microscopy (TEM) and ultraviolet spectroscopy (UV) analyses were carried out to investigate the structural and textural characteristics of the NiO catalyst. According to the XRD and TEM results, the particle size of the NiO catalyst was found to be in the range of 20–80 nm. From the EDX analysis, it was concluded that the NiO catalyst was synthesised in pure form. The potential of the NiO catalyst was tested for the first time in both the photocatalytic reduction of methylene blue (MB) and the generation of hydrogen (H2) from sodium borohydride (NaBH4) hydrolysis. A high decolorization efficiency of 98.09 % and a reuse efficiency of 90.89 % after five recycles were achieved for the photocatalytic reduction of MB using NiO catalyst. The photocatalytic reduction of MB was consistent with the pseudo-first order kinetic model, and the reaction rate constant was found to be 2.55 min−1. The H2 generation rate (RH2) of 922.5 mLH2 min−1 gcat−1 at 70 °C was achieved for the NaBH4 hydrolysis. The kinetics of H2 generation from NaBH4 hydrolysis was studied employing the nth-order and the Langmuir-Hinshelwood models, and the activation energy (Ea) values were found to be 21.29 kJ mol−1 and 22.23 kJ mol−1, respectively. It was concluded that the NiO catalyst prepared by the eco-friendly green synthesis method has a promising potential in both photocatalytic reduction of MB and H2 generation from NaBH4 hydrolysis.

Phytic acid-derivative Co2B-CoPOx coralloidal structure with delicate boron vacancy for enhanced hydrogen generation from sodium borohydride

Application of transition metal boride (TMB) catalysts towards hydrolysis of NaBH4 holds great significance to help relieve the energy crisis. Herein, we present a facile and versatile metal-organic framework (MOF) assisted strategy to prepare Co2B-CoPOx with massive boron vacancies by introducing phytic acid (PA) cross-linked Co complexes that are acquired from reaction of PA and ZIF-67 into cobalt boride. The PA etching effectively breaks down the structure of ZIF-67 to create more vacancies, favoring the maximal exposure of active sites and elevation of catalytic activity. Experimental results demonstrate a drastic electronic interaction between Co and the dopant phosphorous (P), thereby the robustly electronegative P induces electron redistribution around the metal species, which facilitates the dissociation of B-H bond and the adsorption of H2O molecules. The vacancy-rich Co2B-CoPOx catalyst exhibits scalable performance, characterized by a high hydrogen generation rate (HGR) of 7716.7 mL min−1 g−1 and a low activation energy (Ea) of 44.9 kJ/mol, rivaling state-of-the-art catalysts. This work provides valuable insights for the development of advanced catalysts through P doping and boron vacancy engineering and the design of efficient and sustainable energy conversion systems.

Mild Hydrogenation of 2-Furoic Acid by Pt Nanoparticles Dispersed in a Hierarchical ZSM-5 Zeolite.

Hydrogenation of biobased compounds can add value to platform molecules obtained from biomass refining. Herein, we explore the hydrogenation of 2-furoic acid (2-furancarboxylic acid, FCA), a derivative of furfural, with H2 generated in situ by NaBH4 hydrolysis at ambient conditions. Nearly complete conversion of FCA was obtained with tetrahydrofuroic acid (THFA) and 5-hydroxyvaleric acid (5-HVA) as the only two reaction products over Pt nanoparticles supported on hierarchical ZSM-5. Small Pt nanoparticles (2 to 3 nm) were stabilized by ZSM-5 nanosheets. At an optimized Pt loading, the Pt nanoparticles can catalyze the hydrolysis of NaBH4 and the subsequent hydrogenation of FCA with the assistance of Brønsted acid sites. Nanostructuring ZSM-5 into nanosheets and its acidity contributes to the stability of the dispersed Pt nanoparticles. Deactivation due to NaBO2 deposition on the Pt particles can be countered by a simple washing treatment. Overall, this approach shows the promise of mild hydrogenation of biobased feedstock coupled with NaBH4 hydrolysis.

Recoverable sepiolite coated B-CoP/ cellulose hybrid aerogel as monolithic catalysts for hydrogen generation via NaBH4 hydrolysis

Recoverable sepiolite coated B-CoP/ cellulose hybrid aerogel as monolithic catalysts for hydrogen generation via NaBH4 hydrolysis

Hydrogen generation from hydrolysis of NaBH4 solution with efficient g-C3N4/Co–Mo–B/Ni foam catalyst

Sodium borohydride (NaBH4) is considered to be a perfect material for hydrogen production in consideration of the high hydrogen capacity. However, the catalyst with low cost and high activity is the key to achieving dehydrogenation from the hydrolysis of NaBH4 solution. In this work, we successfully synthesized g-C3N4/Co–Mo–B/Ni foam catalyst by means of chemical deposition at 298 K. The catalytic property of g-C3N4/Co–Mo–B/Ni foam for NaBH4 hydrolysis was investigated via regulating the molar ratio of Co2+ and MoO42− (nCo2+:nMoO42−). The results disclosed that the obtained g-C3N4/Co–Mo–B/Ni foam showed the optimum catalytic property when the nCo2+:nMoO42− value was 1:1. Its hydrogen generation rate (HGR) and apparent activation energy (Ea) were respectively determined to be 9957.7 mL min−1·g−1 and 52.6 kJ mol−1 under visible light irradiation, which has obviously exceeded the performance under darkness (HGR = 8372.7 mL min−1·g−1, Ea = 55.8 kJ mol−1). It might attribute to the emergence of Mo2C during the preparation process which attracted the photoelectron transfer on g-C3N4, thus promoting the photocatalytic hydrolytic process of NaBH4 solution. Moreover, the smaller grain size and synergistic effect between multiple components could be another reason for heightening the catalytic dehydrogenation property of g-C3N4/Co–Mo–B/Ni foam catalyst.

Microwave-intensified hydrolysis for high efficiency hydrogen generation over magnetically separable Co3O4-carbon nanotube composites

Microwave (MW)-assisted process intensification technology has the potential to improve catalytic conversion under mild reaction conditions. In this study, a series of MW-sensitive CNTs-Co3O4 composites were designed and synthesized as catalysts for the conversion of NaBH4 to H2. It was found that MW irradiation leads to a 19.6 (35 °C) to 49.5% (55 °C) increase in the hydrogen generation rate (HGR) of NaBH4 hydrolysis catalyzed by the CC14, which is attributed to the combined contribution of thermal and non-thermal effects of microwave irradiation. Moreover, the NaBH4 hydrolysis catalyzed by CC14 catalyst at different heating modes followed the zero-order kinetic model, and the pre-exponential factor of NaBH4 hydrolysis catalyzed by CC14 catalyst under MW irradiation was approximately 157 times higher than under conventional heating, indicating that microwave irradiation increased the effective collision frequency at the reaction interface of CC14 catalyst. In addition, the selective and instantaneous heating of microwave irradiation was demonstrated by using a specially designed pseudo-homogeneous low temperature reaction system. Moreover, DFT calculations show that the rate-determining step of NaBH4 hydrolysis is H2O dissociation.

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 activity of two-dimensional cobalt-ZIF catalyst for NaBH4 hydrolysis

In this work, cobalt-ZIF catalysts were synthesized by water-based synthesis methods. Various hydrogen bond acceptor (tetramethylammonium bromide (TMAB), tetraethylammonium bromide (TEAB), tetrapropylammonium bromide (TPAB), tetrabutylammonium bromide (TBAB) and trimethylphenylammonium bromide (TMPAB)) were co-added during cobalt-ZIF catalyst synthesis procedures to promote the deprotonation of 2-methyl imidazole and the deprotonated 2-methyl imidazole was then further coordinated with cobalt ion to form a ZIF framework. Co-addition of TMPAB during synthesis resulted in 3D imperfect rhombic dodecahedrals with high surface area (432.3 m2/g), while, the rest of used hydrogen bond acceptors (TMAB, TEAB, TPAB and TBAB) provided 2D ZIF-L structure with relatively small surface area and pore volume. All synthesized cobalt-ZIF with different structures and morphologies were used as a catalyst for H2 generation by NaBH4 hydrolysis reaction. It was found that all 2D cobalt-ZIF structures exhibited higher hydrogen production rate than that of the 3D imperfect rhombic dodecahedral structure. This can be explained by the cushion-shaped cavity of a two-dimensional framework exhibiting higher flexibility which can promote more diffusion of reactants than the tetrahedral structure of a 3D-framework. X-ray absorption spectroscopy was used to investigate the electronic state of cobalt and to monitor the changing of cobalt probe atom during hydrolysis reaction. The electronic state of cobalt for all catalysts was Co2+ with the same tetrahedral symmetry. The lowering of pre-edge peaks of cobalt K edge XANES spectra during hydrolysis reaction indicated to distortion of the symmetry which is related to the reduction of the catalytic performance.

3D hollow microrod engineered MOF-derived Cu/Co catalysts promoted by Al nanoflakes for efficient H2 generation through NaBH4 hydrolysis: Perceptions on boosted reaction channels aided by a synergistic effect

Since sodium borohydride (NaBH4) has been broadly recognized as an advantageous hydrogen storage material, it is crucial to develop a proficient catalyst for the innovative and effective use of hydrogen energy for electric vehicles and portable electronic devices. Current work demonstrates the series of designed CRxCT1-x@DABCO-MOF hollow micro rods supported by the active doping of Al nanoflakes as an efficient and stable catalyst for the hydrolysis and electrooxidation of NaBH4. The structural, physicochemical, thermal and electrochemical features of the prepared MOF catalysts have been investigated through various analytical techniques. As per the experimental results, Al-8/CR/CT-2@DABCO-MOF has exhibited outstanding performance of 633.90 mL hydrogen production through the hydrogen generation rate of 423.40 mLg−1min−1 and activation energy of 38.66 kJmol−1. Besides that Al-8/CR/CT-2@DABCO-MOF catalyst also exhibited excellent electrooxidation properties. The outstanding activity was credited to the catalytic synergistic effect among the Co, Cu and Al as well as the unique structure provided by Al nanoflakes which offered high surface area with more active sites and high stability to MOF structure which enabled the intimate contact between water molecules and the surface of the MOF and hence maximum H2 was produced. Overall this MOF structure claimed their potential candidature for portable hydrogen devices.

Synthesis of Trimetallic Nanoparticle (NiCoPd)-Supported Carbon Nanofibers as a Catalyst for NaBH4 Hydrolysis.

The generation of H2 via the catalytic hydrolysis of sodium borohydride (SBH) has promise as a practical and secure approach to produce H2, a secure and environmentally friendly energy source for the foreseeable future. In this study, distinctive trimetallic NiCoPd nanoparticle-supported carbon nanofibers (NiCoPd tri-NPs@CNFs) is synthesized via sol-gel and electrospinning approaches. The fabricated trimetallic catalysts show an excellent catalytic performance for the generation of H2 from the hydrolysis of SBH. Standard physicochemical techniques were used to characterize the as-prepared NiCoPd tri-NPs@CNFs. The results show that NiCoPd tri-NPs@CNFs is formed, with an average particle size of about 21 nm. When compared to NiCo bimetallic NP @CNFS, all NiCoPd tri-NPs@CNFs formulations demonstrated greater catalytic activates for the hydrolysis of SBH. The improved catalytic activity may be due in the majority to the synergistic interaction between the three metals in the trimetallic architecture. Furthermore, the activation energy for the catalytic hydrolysis of SBH by the NiCoPd tri-NPs@CNFs was determined to be 16.30 kJ mol-1. The kinetics studies show that the reaction is of a first order with respect to the catalyst loading amount and a half order with respect to the SBH concentration [SBH].

Boosting borohydride hydrolysis for H2 generation by MOF-templated void-engineered shaggy cobalt oxide: Abundant oxygen vacancy-mediated enhancement

Designing an advantageous catalyst for enhancing the release of hydrogen (H2) from NaBH4 hydrolysis is still desirable. Herein, a void-engineered shaggy cobalt oxide (VSCO) is constructed via facile carving and calcination using the cuboid cobalt-based metal organic framework (Co-MOF) as a template. The as-prepared VSCO shows unique structural properties, such as large internal void, high specific surface area, and abundant oxygen vacancy, enabling VSCO to boost H2 production from NaBH4 hydrolysis. VSCO also exhibits an activation energy (Ea) of 28.9 kJ mol−1, which is much lower than that of commercial Co3O4 NP (62.9 kJ mol−1) and most of recent reported noble metals. VSCO also retains its outstanding catalytic activity over multiple cycles. This work sheds a light into the new approach of constructing metal oxide material with the void structure and abundant oxygen vacancies for catalyzing the hydrolysis of NaBH4.

Ni-BTC-derived CoP-NiCoP/NC microspheres as an efficient catalyst for NaBH4 hydrolysis

The development of a low cost, high performance and stable catalyst is an important prerequisite for the widespread application of efficient hydrogen production from sodium borohydride (NaBH4). Herein, Ni-BTC is derived into CoP-NiCoP/NC catalyst consisting of CoP-NiCoP nanorods and nitrogen-doped carbon (NC) microsphere by hydrothermal and gas-phase phosphorylation methods. The CoP-NiCoP/NC catalyst exhibits good catalytic activity, with a high hydrogen evolution rate of NaBH4 reaching 7052 mL·min−1·g−1 at 303 K, and an activation energy of only 35.57 kJ·mol−1. This is significantly better than most catalysts reported previously. In addition, the CoP-NiCoP/NC catalyst demonstrates good durability with 75 % of the original catalytic activity after 10 performance testing. This excellent catalytic performance is achieved thanks to its porous microsphere structural design and the cooperative effect between CoP and NiCoP. This catalyst with high catalytic performance and mild preparation conditions is promising for future actual applications.