Hydrogen Generation Rate Research Articles

Synthesis and catalytic performance of nanoflower-like Ru@CoAl-LDH composite catalyst for NaBH4 hydrolysis

Sodium borohydride (NaBH4) has been widely regarded as the one of most promising future hydrogen (H2)-generated materials. Therefore, it is necessary to find a catalyst with higher catalytic performance to promote the on-demand H2 release of NaBH4 hydrolysis. In this study, a [email protected] catalyst was developed by immobilizing Ru nanoparticles (Ru NPs) on the surface of Co Al Layered Double Hydroxide (CoAl-LDH) nanocurds. The Ru NPs were prepared by H2 reduction, and nanoflower-like CoAl-LDH was synthesized through a one-step solvothermal method. The microstructure and composition of the catalysts were investigated through scanning electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The results showed that [email protected] exhibited good catalytic performance toward the NaBH4 hydrolysis. At 30 °C, the hydrogen generation rate of the hydrolysis reaction was 44.34 L·min−1·gRu−1, and the reaction activation energy was 38.83 kJ·mol−1, and superior to many catalysts of the same type. Because of its high activity, low activation energy and excellent economic performance, this catalyst has high potential for applications in NaBH4 hydrolysis.

Solar-driven wastewater treatment coupled with hydrogen and electricity production via a bismuth-doped TiO2 nanorod array

An ingenious and unassisted solar-driven wastewater resourcezation system (SDWRS) was designed by connecting a silicon cell (SC) to the back of a bismuth-doped TiO2 nanorod array (BTNR) for efficient water treatment accompanying hydrogen and electricity generation. Doping of Bi effectively improved the charge-transfer property and donor density of the BTNR. In addition, the introduction of SC provided an inner bias much higher than conventional photocatalytic fuel cells (PFCs) to drive efficient electron transfer from the photoanode to cathode by absorbing the transmitted longer wavelength photons. Therefore, compared with pure TNR, the photocurrent density of BTNR at 0.8 V vs Ag/AgCl is greatly increased to ∼2.81 mA cm−2. Due to the enhanced light utilization and charge transfer, which derived from the synergistic effect between the BTNR and SC, the assembled SDWRS displayed the outstanding tetracycline (TC) degradation together with hydrogen and electricity production. A TC removal ratio of nearly 100% after 2.5 h of operation, an average hydrogen generation rate of ∼29.08 μmol h−1 cm−2, and an electricity output with a maximum power output of ∼632.8 μW cm−2 were achieved. The results also manifested that SDWRS had great application potential for degrading various refractory pollutants from wastewater for clean energy production.

Rational 3D Structure of Monolithic Catalysts for Enhanced Hydrolytic Dehydrogenation of Ammonia Borane

Monolithic catalysts have irreplaceable advantages in hydrogen (H2) production through catalytic dehydrogenation from liquid-phase hydrogen storage materials. However, monolithic catalysts suffer from an inevitable reduction in accessible active sites due to the reduced specific surface area and hindered mass transfer. Therefore, a rational three-dimensional (3D) structure of monolithic catalysts is needed to adjust the structural factors for maximizing performance. Herein, a series of efficient and low-cost 3D catalysts with designed periodic structures were successfully fabricated. Due to the optimized specific surface area and bubble transport of the elaborate 3D structure, compared to the disordered foam structure, the new series of monolithic catalysts showed 2.3- and 1.6-fold improvement in overall catalytic performance at 298 and 318 K without any change in physiochemical characteristics, with hydrogen generation rates of 2548 and 3885 mL gcat–1 min–1, respectively. In addition, a three-period structural design philosophy for 3D catalysts was summarized, and the concept of surface activity was introduced to provide quantifiable criteria for guidance of structural optimization. The outcomes in this paper may open up new insights for building high-efficiency monolithic catalysts.

Hydrogen generation by hydrolysis of solid sodium borohydride for portable PEMFC applications

In this paper, the hydrogen generation by the hydrolysis of solid sodium borohydride was studied. A novel NiCoP/RC catalyst that loads Ni, Co, and P complexes on resin carbon (RC) was prepared to accelerate the hydrolysis. The hydrogen generation rate, reaction temperature, hydrogen output and water-hydrogen ratio during the reaction were recorded. In comparison to the commonly used cobalt chloride catalyst, the NiCoP/RC catalyst demonstrated superior catalytic activity. Citric acid was used to neutralize the alkaline by-products, and while the mixture of NiCoP/RC catalyst and citric acid increased the hydrogen output, it resulted in lower water utilization rate. Therefore, intermittent water feeding from the bottom of the reactor was proposed, which was found to be beneficial in terms of both hydrogen output and water utilization. Finally, the study warns about the potential for thermal runaway during the hydrolysis reaction of solid sodium borohydride.

Co/Fe3O4@GO catalyst for one-step hydrogen generation from hydrolysis of NaBH4: Optimization and kinetic study

In this study, cobalt nanocatalysts supported on the Fe3O4@GO were synthesized for boosting hydrogen generation upon hydrolysis of sodium borohydride. Co/Fe3O4@GO catalysts were synthesized through a facile co-precipitation method followed by a chemical reduction step. The prepared samples were characterized using various techniques including X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Field emission scanning electron microscopy (FE-SEM), Vibrating sample magnetometer (VSM), and Nitrogen adsorption–desorption (BET). Benefiting from the high crystallinity, good dispersion of Co nanoparticles over the Fe3O4@GO, and the synergistic effect between Co nanoparticles and Fe3O4@GO support, Co/Fe3O4@GO catalysts with 30 wt% cobalt loading showed the highest catalytic activity with high hydrogen generation rate of 4000 mL/min.gcat and relatively good stability. To investigate the effect of the parameters on hydrogen generation rate and optimal reaction conditions, the Box-Behnken design under response surface methodology (RSM) was applied. ANOVA results denoted that the temperature with the highest F-value and lowest P-value had the most effect on the hydrogen generation rate. Under the optimum conditions including a temperature of 39.83 °C, 17.74 mg of catalyst, and 5.135 wt% NaBH4 concentration, Co(30%)/Fe3O4@GO exhibited a superior H2 generation rate of 6005 mL/min.gcat and low activation energy of 44.4 kJ/mol. Therefore, the Co/Fe3O4@GO is a promising catalyst for NaBH4 hydrolysis due to its easy preparation and separation method, high hydrogen generation rate, and low activation energy.

Ultrathin Defective Nanosheet Subunit ZnIn2S4 Hollow Nanoflowers for Efficient Photocatalytic Hydrogen Evolution

Constructing hierarchical and ultrathin‐structured metal sulfides is beneficial for achieving high‐efficiency hydrogen evolution catalysts. Herein, ZnIn2S4 (ZIS) hollow nanoflowers (HNFs) composed of ultrathin nanosheets are creatively synthesized via a facile trisodium citrate‐mediated and stirring‐assisted solvothermal method. Experimental results reveal that the synergy effect of ethanol, trisodium citrate, and continuous stirring during solvothermal synthesis process play a significant role in optimizing microstructure as well as physicochemical properties of as‐prepared ZIS samples. Importantly, the fabricated ZIS HNFs with the thinnest nanosheets (2.28 nm) manifest the highest average photocatalytic hydrogen generation rate of 301.5 μmol h−1, which is 2.3 times higher than that of the pristine ZIS microspheres composed of nanoparticles with Pt as the cocatalyst and triethanolamine (TEOA) as the sacrificial agent and outperforms most reported ZnIn2S4‐based materials under similar testing conditions. Moreover, the optimized sample also shows a hydrogen generation rate of 0.53 μmol h−1.in pure water without any cocatalyst. This controllable agitation of the reaction mixture during the hydro/solvothermal synthesis process offers an eco‐friendly and scalable approach for tuning the microstructure of nanomaterials with enhanced performance for various applications.

In situ growing of zero-valent aluminium nanoparticles for the concurrent hydrogen production and chromium removal from artificial wastewater

The development of novel single-pot technologies to address multiple complications is always challenging in the contemporary world. The current research work intends to assess the hydrogen generation system along with the simultaneous chromium removal. The method of in-situ formation of zero-aluminium (Al(0)) nanoparticles is accomplished in an aqueous medium with the aid of aluminium salt and sodium borohydride. This multifunctional process can completely remove hexavalent chromium (Cr(VI)) along with concurrent maximum hydrogen generation rate of 550 mL/min at pH 3.0. The experimental analyses are done to scrutinize the effect of parameters such as reactant chemicals dosage, pH conditions, initial Cr(VI) concentration, temperature, presence of organic carbon as phenol, and water matrices on the reduction of Cr(VI) and hydrogen production. The results elucidate that the process can be widely utilized in the range of pH 3.0 – 11.0; the maximum hydrogen yield was improved from 150 to 570 mL/min and the Cr(VI) removal efficiency was improved from 94.8% to 100% by changing the quantity of aluminium salt from 0.1 to 0.6 g per 50 mL of Cr(VI) containing artificial wastewater. Cr(VI) in conjunction with phenol removal studies along with simultaneous hydrogen generation is also explored, featuring this technology as energy positive for the co-removal of pollutants.

Facile construction of robust Ru-Co3O4 Mott-Schottky catalyst enabling efficient dehydrogenation of ammonia borane for hydrogen generation

Developing efficient catalysts for the dehydrogenation of ammonia borane (AB) is important for the safe storage and controlled release of hydrogen, but it is a challenging task. In this study, we designed a robust Ru-Co3O4 catalyst using the Mott-Schottky effect to induce favorable charge rearrangement. The self-created electron-rich Co3O4 and electron-deficient Ru sites at heterointerfaces are indispensable for the activation of the B-H bond in NH3BH3 and the OH bond in H2O, respectively. The synergistic electronic interaction between the electron-rich Co3O4 and electron-deficient Ru sites at the heterointerfaces resulted in an optimal Ru-Co3O4 heterostructure that exhibited outstanding catalytic activity for the hydrolysis of AB in the presence of NaOH. The heterostructure had an extremely high hydrogen generation rate (HGR) of 12238 mL min−1 gcat-1 and an expected high turnover frequency (TOF) of 755 molH2 molRu-1 min−1 at 298 K. The activation energy needed for the hydrolysis was low (36.65 kJ mol−1). This study opens up a new avenue for the rational design of high-performance catalysts for AB dehydrogenation based on the Mott-Schottky effect.

Nanoarchitecture of a Ti3C2@TiO2 Hybrid for Photocatalytic Antibiotic Degradation and Hydrogen Evolution: Stability, Kinetics, and Mechanistic Insights.

Designing of a visible-light-driven semiconductor-based heterojunction with suitable band alignment and well-defined interfacial contact is considered to be an effective strategy for the transformation of solar-to-chemical energy and environmental remediation. In this context, MXenes have received tremendous attention in the research community due to their merits of abundant derivatives, elemental composition, excellent metallic conductivity, and surface termination groups. Meanwhile, a facile synthetic strategy for MXene-derived TiO2 nanocomposites with stable framework and higher photocatalytic activity under visible-light irradiation still remains a challenge for researchers. Herein, we report a novel synthetic strategy of preparing a two-dimensional Ti3C2@TiO2 nanohybrid by a facile reflux method under acidic conditions. In this oxidation reaction, protonation of the hydroxyl terminal group of MXene creates Ti more electrophilic and susceptible to an oxidative nucleophilic addition reaction with the presence of both water and oxygen. The physicochemical properties of the nanohybrid Ti3C2@TiO2 were verified by varieties of characterization techniques. High-resolution transmission electron microscopy and X-ray photoelectron spectroscopy analysis specifically elucidated the intimate interfacial interaction between Ti3C2 and TiO2. The optimized Ti3C2@TiO2-48 h photocatalyst exhibited the highest tetracycline hydrochloride (TCH, 90% in 90 min) degradation efficiency in comparison to pristine TiO2 with a rate constant (k) of 0.02463 min-1. The major contribution of •O2- and •OH radicals throughout photocatalytic TCH degradation was confirmed by the trapping experiment. Moreover, the photocatalyst showed the highest hydrogen generation rate of 140.8 μmol h-1 along with an apparent conversion efficiency of 2.2%. The excellent photocatalytic activity of Ti3C2@TiO2 originated from the superior electrical conductivity of cocatalyst Ti3C2, which facilitated spatial photogenerated e-/h+ separation and transfer at the Ti3C2 MXene@TiO2 interface. Overall, this research work will describe a promising protocol of designing MXene-derived photocatalysts toward efficient environmental remediation and wastewater treatment applications.

PDMA cryogel beads as a catalyst for hydrogen generation from NaBH4 alcoholysis

Poly[2-(dimethylamino)ethyl methacrylate] cryogel beads were prepared under cryogenic conditions via free radical polymerization and used as a catalyst in the production hydrogen (H2) from NaBH4 by alcoholysis. The efficiency of the catalyst was investigated in the range of 0–40 °C by both methanolysis and ethylene glycolysis reactions, and its reuse was tested. Accordingly, it was observed that the methanolysis reaction was faster than the ethylene glycolysis reaction. When the hydrogen generation rate (HGR) values between 0 and 40 °C were compared, it was concluded that the methanolysis reaction rate increased from 1550 to 4800 mL.min−1g−1 and the ethylene glycolysis reaction rate increased from 923 to 3551 mL.min−1g−1. In the alcoholysis reaction catalyzed by PDMA cryogel beads, the activation energy was calculated as 19.34 and 22.77 kJ.mol−1 for the methanolysis and ethylene glycolysis reactions, respectively. After six repetitions, the catalyst activity was calculated over 50% for NaBH4 methanolysis and ethylene glycolysis.

N-doped carbon nanotubes enhanced charge transport between Ni nanoparticles and g-C3N4 nanosheets for photocatalytic H2 generation and 4-nitrophenol removal

Carbon nanotubes with well conductivity can improve photogenerated carrier separation and transport for enhanced photocatalytic performance. In this paper, Ni nanoparticles embedded N-doped carbon nanotubes (CNTs) were decorated on superior thin g-C3N4 nanosheets as a co-catalyst via a mechano-chemical pre-reaction and thermal polymerization at high temperature. The admirable conductivity and unique one-dimensional structure of Ni-decorated CNTs (NiCNTs) generated more active sites and supplied efficient charge transfer. Abundant unpaired electron and π-conjugated structure of N-doped CNTs promoted the delocalization, retarded recombination, and stabilized charge separation. Ni nanoparticles acted as active sites to trap photogenerated electrons for photoreduction reaction. g-C3N4/NiCNTs composites with an optimized ratio revealed a hydrogen (H2) generation rate as high as 1050.4 μmol g−1 h−1, exhibiting an increase of ∼137 times compared with pure g-C3N4 without using Pt as co-catalyst. The H2 generation rate was even higher than that of g-C3N4/Pt, suggesting that NiCNTs can substitute noble metals completely. In addition, the g-C3N4/NiCNTs sample removed 4-nitrophenol (4-NP) within 10 min under visible light irradiation. The rate constant of g-C3N4/NiCNTs sample was ∼49 times of that of pristine g-C3N4. This work proposed a novel bifunctional catalyst for pollutant treatment and clean energy production.

Synthesis of cobalt-doped catalyst for NaBH4 hydrolysis using eggshell biowaste

In the present study, a cobalt-doped catalyst was prepared from chicken eggshell powder (CEP) biowaste to be used in the hydrolysis of sodium borohydride (NaBH4). In the presence of the prepared catalyst (CEPcat), possible effects of the parameters of NaOH concentration (%), catalyst amount (g), NaBH4 concentration (%), process temperature (oC) and reusability affecting the hydrolysis of sodium borohydride were examined. The CEPcat obtained was characterized with FT-IR, TGA, XRD, SEM and EDX analyses. The hydrogen generation rate (HGR) was determined as 432 mL gCo−1 min−1 in the presence of 1 g CEPcat, a CoO/CaO ratio of 10/90 and 1% NaBH4 concentration. The activation energy of the NaBH4 hydrolysis reaction was calculated as 16.78 kJ mol−1. After 16 reuses of the CEPcat there was no significant decrease in the hydrogen volume. Compared to the first use while there was an increase in the HGR. These results showed that the CEPcat prepared has a significant advantage over other catalysts for use in NaBH4 hydrolysis.

Gamma-ray-irradiated construction of CuCo-based nanocomposites for attractive hydrogen production and tandem hydrogenation

Nitroarenes are important chemicals but display toxity to environment and organisms. In the present work, non-precious bicomponent CuCo-based nanocomposites (CuCo2O4/CuO) prepared with the aid of gamma(γ)-ray-irradiation were utilized for hydrogen production from ammonia borane (AB) hydrolysis and tandem hydrogenation of nitroarenes. The γ-ray-irradiation remarkably boosted the catalytic performance for the AB dehydrogenation and the hydrogenation of nitroarenes. Hydrogen generation rate (HGR) for the CuCo2O4/CuO catalyst reached 856.3 mL min−1·gcat−1, which was approximately two-fold than that of the catalyst prepared by conventional method (only 397.1 mL min−1·gcat−1). Meanwhile, this irradiation-induced catalyst also showed excellent performance for the hydrogenation of screened nitroarenes with 100% yield of the corresponding amines. The CuCo2O4/CuO catalyst exhibited high reusability with ∼90% remained activity of the initial one after six runs. The bicomponent CuCo2O4/CuO exhibited positive hydrogen spillover and synergistic effects contributing to the considerable activity improvement, which is beneficial to the detoxication, conversion and utilization of poison nitroarenes.

Photocatalytic Activity and Stability of Organically Modified Layered Perovskite-like Titanates HLnTiO4 (Ln = La, Nd) in the Reaction of Hydrogen Evolution from Aqueous Methanol

Two series of hybrid inorganic–organic materials, prepared via interlayer organic modification of protonated Ruddlesden–Popper phases HLnTiO4 (Ln = La, Nd) with n-alkylamines and n-alkoxy groups of various lengths, have been systematically studied with respect to photocatalytic hydrogen evolution from aqueous methanol under near-ultraviolet irradiation for the first time. Photocatalytic measurements were organized in such a way as to control a wide range of parameters, including the hydrogen generation rate, quantum efficiency of the reaction, potential dark activity of the sample, its actual volume concentration in the suspension, pH of the medium and stability of the photocatalytic material under the operating conditions. The insertion of the organic modifiers into the interlayer space of the titanates allowed obtaining new, more efficient photocatalytic materials, being up to 68 and 29 times superior in the activity in comparison with the initial unmodified compounds HLnTiO4 and a reference photocatalyst TiO2 P25 Degussa, respectively. The hydrogen evolution rate over the samples correlates with the extent of their interlayer hydration, as in the case of the inorganic–organic derivatives of other layered perovskites reported earlier. However, the HLnTiO4-based samples demonstrate increased stability with regard to the photodegradation of the interlayer organic components as compared with related H2Ln2Ti3O10-based hybrid materials.

Significant improvement of TiO2 photocatalytic hydrogen generation by photothermic synergistic action and underlying mechanism

This article reported an extremely easy method of optical radiation-assisted thermal excitation to dramatically increase photocatalytic hydrogen generation ability of water splitting with P25 as a model compound. This method compensated for the time waste, high cost and operational complexity of traditional catalytic material modification methods, and largely improved the photocatalytic hydrogen production ability of photocatalytic materials. The hydrogen generation rates at room temperature is 1090 μmol/g/h. At 50 °C, the rate increase to 10670 μmol/g/h. The quantum rates at room temperature and 50 °C are 6.5 and 63.3, respectively. It is clear that appropriate low-temperature heating could largely accelerate the hydrogen generation rate of P25.This work presents the detailed mechanism how this method largely enhances photocatalytic hydrogen generation of P25 as well as the laws. The new method offers some evidences and reference for research on how the photothermic synergistic action facilitates the photocatalytic hydrogen generation of catalytic materials.

Hierarchical nanohybrid of CuS/NiS2/Ti3C2 heterostructure with boosting charge transfer for efficient photocatalytic hydrogen evolution

Fabricating heterostructure photocatalysts with co-catalysts can improve the separation and transfer of photo-induced electrons and holes for photocatalysis reactions. Herein, Ti3C2Tx nanosheets are obtained by chemical etching via the hydrothermal route and serve as a template for growing photocatalysts. NiS2 nanoparticles and CuS nanoneedles are deposited sequentially on the surface of Ti3C2Tx nanosheets to form “Type II” CuS/NiS2/Ti3C2Tx hierarchical heterostructure via the solvothermal method. The enormous nanoneedles morphology provides enlarged active sites for the photocatalytic processes. The fabricated CuS/NiS2/Ti3C2Tx heterostructure delivers an increased hydrogen generation rate of 32.66 mmol g−1 h−1, which is higher than that of pure CuS (2.38 folds), NiS2 (1.93 folds), and NiS2/Ti3C2Tx (1.71 folds). CuS/NiS2/Ti3C2Tx heterostructure also performs a superior hydrogen evolution retention of 97.7% after 4 cycles (one cycle lasts 4 h), implying its decent structural stability and light corrosion resistance. The reasons are ascribed to the constructed “Type II” heterostructure of CuS/NiS2 with higher active sites, improved conductivity, and efficient separation of electrons and holes. DFT calculation and Mott-Schottky plots results elucidate the formation mechanism of CuS/NiS2/Ti3C2Tx “Type II” structure. CuS/NiS2/Ti3C2Tx heterostructure also obtains a reduced bandgap with increased light absorption. The van der Waals force between 2D materials enhances the transfer of photo-generated electrons. This work demonstrates that designing hierarchical co-catalyst heterostructure without non-noble can effectively promote water splitting in the solar-to-chemical system.

Aerogel of chitosan/graphene oxide loaded Ru-CoP as a monolithic catalyst for hydrogen generation via NaBH4 hydrolysis

Powder type catalysts aren’t often easily recycled after use and resulted in water pollution for hydrogen production by NaBH4 hydrolysis. Based on this, Ru-CoP is firstly anchored on the surface of graphene oxide (GO) by in-situ growth of ZIF-67, water etching, phosphating and loading Ru, then a novel composite aerogel-type catalyst is fabricated with chitosan (CS), GO and Ru-CoP@GO by the facile freeze-drying method. The results show that the hydrogen generation rate (HGR) of Ru-CoP@GO is 7200mLmin−1gcatalyst−1, and the activation energy is 47.7 kJ mol−1, which is not only the sheet catalyst with high catalytic performance, but also the excellent filler for composite aerogel, attributed to the strong interaction between Ru and Co species. Meanwhile, by regulating the amounts of CS, GO and Ru-CoP@GO, the loss rate of Ru-CoP@GO/CS aerogel is only 23% at the hydrogen generation rate (4712mLmin−1gcatalyst−1) after five cycles of catalytic testing, which is due to structural coupling action and the formation of amide bond between Ru-CoP@GO, CS and GO, demonstrating an excellent structural stability. This work provides a precise and controllable strategy for the development of monolithic catalysts.

Magnetic dendritic KCC-1 nanosphere-supported cobalt composite as a separable catalyst for hydrogen generation from NaBH4 hydrolysis

The introduction of magnetism into a catalyst can greatly optimize its separation performance. In the present work, a kind of magnetically separable catalysts for promoting NaBH4 hydrolysis have been fabricated by anchoring cobalt nanoparticles on magnetic dendritic KCC-1 nanospheres composed of magnetic Fe3O4 core and fibrous shell. The fabricated catalysts were characterized with various characterization methods, including absorption spectroscopy (AAS), scanning electron microscopy (SEM), high-resolution transmission electronic microscopy (HRTEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometry (VSM), and Fourier transform infrared (FT-IR), etc. This kind of catalysts exhibit high catalytic activity for promoting the hydrolysis of NaBH4 under alkaline conditions, giving a hydrogen generation rate and activation energy of 3.83 L min−1 gCo−1 (30 °C) and 53.63 kJ mol−1, respectively. After used for 5 cycles, the catalyst showed 36.5% catalytic activity reserved. Most importantly, the magnetism of the catalyst made it easily separated and recycled from the solution after the reaction completed. The development of this kind of catalysts could provide a promising option for catalyzing NaBH4 hydrolysis for portable hydrogen production from.

A facile preparation of graphene hydrogel-supported bimetallic RuM (M: Co, Ni, Cu) nanoparticles as catalysts in the hydrogen generation from ammonia borane

Abstract The synthesis of ultrafine well-dispersed bimetallic RuM (M: Co, Ni, Cu) nanoparticles (NPs) supported on graphene hydrogel (GH) was accomplished by a novel one-pot wet-chemical protocol that comprised the hydrothermal reduction of the mixture of graphene oxide and metal precursors by ethylene glycol (EG) in a Teflon-coated stainless-steel reactor at 180 °C. In this study, for the first time, we report the synthesis of bimetallic RuM NPs anchored on GH during the hydrothermal production of GH from graphene oxide (GH-RuM) and the catalysis of the yielded GH-Ru in the hydrolysis of ammonia borane (AB). As-synthesized GH-RuM (M: Co, Ni, Cu) nanocatalysts were characterized by using many advanced instrumental techniques including TEM, XRD, XPS, and ICP-MS. The bimetallic catalysts denoted as GH-Ru20Co80, GH-Ru30Ni70 and GH-Ru10Cu90 exhibited much higher catalytic activity compared to their Ru, Co, Ni and Cu monometallic counterparts in the hydrolytic dehydrogenation of AB. The catalytic performance of as-prepared NPs in terms of hydrogen generation rate (HGR) was achieved in the order of RuCo > RuNi > RuCu and the highest HGR calculated for the catalyst GH-Ru20Co80 reached 8911.5 mL H2 gcat −1 min−1 at room temperature with an activation energy of 52.5 kJ mol−1.

Hydrogen production from hydrolysis of NaBH4-NH3BH3 composite catalyzed by porous spherical Co3O4

NaBH4-NH3BH3 composite (xSB-AB, x is the molar ratio of SB to AB) has better hydrolysis performance than its monomer, but the hydrogen generation rate (HGR) and hydrogen yield (HY) are still not ideal at room temperature. In this work, a low cost and easily available commercial porous spherical Co3O4 was successfully used to catalyze the hydrolysis of xSB-AB composite. It was found that Co3O4 showed good catalytic performance for the hydrolysis of xSB-AB, and the HY and hydrogen release efficiency (HRE) of 4SB-AB/10 wt%Co3O4 at 40 ℃ reached 2,279.71 mL·g-1 and 89.13%, respectively.