Performance of supported Au–Co alloy as the anode catalyst of direct borohydride-hydrogen peroxide fuel cell

Au–Co alloys supported on Vulcan XC-72R carbon were prepared by the reverse microemulsion method and used as the anode electrocatalyst for direct borohydride-hydrogen peroxide fuel cell (DBHFC). The physical and electrochemical properties were investigated by energy dispersive X-ray (EDX), X-ray diffraction (XRD), cyclic voltammetry, chronamperometry and chronopotentiometry. The results show that supported Au–Co alloys catalysts have higher catalytic activity for the direct oxidation of BH₄⁻ than pure nanosized Au catalyst, especially the Au₄₅Co₅₅/C catalyst presents the highest catalytic activity among all as-prepared Au–Co alloys, and the DBHFC using the Au₄₅Co₅₅/C as anode electrocatalyst shows as high as 66.5 mW cm⁻² power density at a discharge current density of 85 mA cm⁻² at 25 °C.     

Studies of electrochemical performance of carbon supported Pt-Cu nanoparticles as anode catalysts for direct borohydride-hydrogen peroxide fuel cell

Carbon supported Pt-Cu bimetallic nanoparticles are prepared by a modified NaBH₄ reduction method in aqueous solution and used as the anode electrocatalyst of direct borohydride-hydrogen peroxide fuel cell (DBHFC). The physical and electrochemical properties of the as-prepared electrocatalysts are investigated by transmission electron microscopy (TEM), X-ray diffraction (XRD), cyclic voltammetry (CV), chronoamperometry (CA), chronopotentiometry (CP) and fuel cell test. The results show that the carbon supported Pt-Cu bimetallic catalysts have much higher catalytic activity for the direct oxidation of BH₄⁻ than the carbon supported pure nanosized Pt catalyst, especially the Pt₅₀Cu₅₀/C catalyst presents the highest catalytic activity among all as-prepared catalysts, and the DBHFC using Pt₅₀Cu₅₀/C as anode electrocatalyst and Pt/C as cathode electrocatalyst shows as high as 71.6 mW cm⁻² power density at a discharge current density of 54.7 mA cm⁻² at 25 °C.     

The effect of gold on the copper-zinc oxides catalyst during the partial oxidation of methanol reaction

Hydrogen production resulting from the partial oxidation of methanol (POM) was investigated using copper-zinc-supported gold catalysts. The influence of oxygen concentration on activity and initiation temperature (T_i) over Au_4.3CZ (ca. 4.3 wt.% Au, 32.3 wt.% Cu and 63.4 wt.% Zn) catalysts was compared with CZ (ca. 31.7 wt.% Cu and 68.3 wt.% Zn) catalysts. The Au_4.3CZ catalyst was able to react at temperatures lower than 195 °C, while CZ catalyst could not be initiated without pre-activation. In addition, Au_4.3CZ performed higher hydrogen selectivity and lower carbon monoxide selectivity than CZ catalyst. The addition of gold might induce a change in the reducibility of copper species and result in the more active species, Cu⁰ and Cu⁺, on the catalytic surface and, especially, enhance the adsorption of oxygen and methoxy group at low temperature. These adsorbed oxygen atoms could be removed as CO₂, which speed up the rate-determining step of POM. It might influence initiation temperature and catalytic performance, i.e. the POM reaction can be initiated at T_i: 120 °C, with catalytic performance at 95% methanol conversion, 97% hydrogen selectivity, and 5.5% carbon monoxide selectivity at 190 °C over Au_4.3CZ without pre-activation.     

Comparison of electrocatalytic activity of carbon-supported Au–M (M = Fe,Co, Ni,Cu and Zn) bimetallic nanoparticles for direct borohydride fuel cells

The Au–M (M = Fe, Co, Ni, Cu and Zn) bimetallic nanoparticles supported on the Vulcan XC-72R (Au–M/C) were synthesized by a reverse micelle method. The structures and compositions of the carbon supported Au–M catalysts were characterized by X-ray diffraction (XRD), energy dispersive X-ray analysis (EDS). The electrocatalytic activity of the Au–M bimetallic nanoparticles with respect to borohydride electro-oxidation for the application of fuel cell was investigated by voltammetry, chronoamperometry and chronopotentiometry. The results showed that alloying Au with 3d transition metals Fe, Co, Ni, Cu or Zn, a metal that leads to the maximum eight-electron oxidation of BH₄⁻, not only improved the electrode kinetics of BH₄⁻ oxidation but also reduced catalyst cost. Among the various investigated Au–M/C electrocatalysts, the Au–Zn, Au–Fe and Au–Cu catalysts showed no activity of NaBH₄ hydrolysis, and Au–Zn presented an attractive catalytic activity for borohydride oxidation.     

Selective deposition of gold onto Pt sites in Pt/C catalysts: Electron microscopy and electrochemical characterization

This work aims to study the selective deposition of gold onto the faces of Pt^o in Pt/C catalyst. The preparation of monometallic Pt/C catalyst was carried out by means of the impregnation of platinum over graphite. The bimetallic catalyst Pt–Au/C was prepared by selectively depositing Au on supported monometallic Pt/C catalyst by means of the reduction “in-situ” of AuCl₄⁻. The surface redox method used in this work was the Refilling method (RE), which consisted in adsorbing hydrogen first on the metal (Pt), and subsequently reducing the AuCl₄⁻ species by contact with the Pt–H interface at low temperature. The catalysts were characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM), whereas for the electrochemical tests the catalysts were supported on Vulcan XC-72 carbon and they were evaluated by linear and cyclic voltammetry as well as rotating disk electrode (RDE) measurements. The composition of the individual metal particles of the solids indicated the presence of both metals, Pt and Au. The results indicated that a partial Au coating of certain Pt facets is possible, which indicates that the coating mechanism is selective and could influence the catalytic properties of the bimetallic Pt–Au/C catalysts. As a result of this blockage we observed a reduction of the catalytic activity of the bimetallic catalyst with respect to the Pt/C catalyst. The electrochemical characterization showed a Tafel slope of −94 mV dec⁻¹ for the Pt–Au/C sample, with a 0.62 transfer coefficient, showing the effect of the blockage of the active platinum sites.     

Highly efficient Au/ZrO2 catalysts for low-temperature water–gas shift reaction: Effect of pre-calcination temperature of ZrO2

A series of Au/ZrO₂ catalysts with low content of gold (<1 wt.%) were prepared by deposition–precipitation method and evaluated in the low-temperature water–gas shift reaction (WGSR) under H₂-rich reformate atmosphere. The effect of pre-calcination temperature of ZrO₂ on the structural and surface properties of the freshly reduced Au/ZrO₂ catalysts was investigated by XRD, N₂-physisorption, HRTEM, UV–Vis DRS, AAS, EPR and XPS characterizations. The catalytic evaluation results reveal that the one supported on ZrO₂ calcined at 350 °C shows the best catalytic performance. Correlating to the characterization results, it is found that the catalytic performance of Au/ZrO₂ catalysts strongly depends on the concentration of F-center defects on ZrO₂ surface. EPR and XPS results disclose that electrons can be transferred from F-center to the supported Au, resulting in the formation of activated electron-rich Au cluster, which is responsible for the high catalytic activity of the Au/ZrO₂ catalysts. Moreover, the electron transfer leads to the firm anchoring of Au cluster by the F-center, thus favoring a high catalytic stability. It is proposed that the active site for WGSR on the Au/ZrO₂ catalysts can be expressed as Au^δ−[V_o⁻]Zr³⁺, where [V_o⁻] represents an F-center.     

Highly active carbon nanotube supported PdAu alloy catalysts for ethanol electrooxidation in alkaline environment

At present, ethanol electrooxidation study is performed on CNT supported Pd and PdAu catalysts to investigate the effect of Au addition to Pd towards the ethanol electrooxidation activity. NaBH₄ reduction method is employed for the synthesis of Pd/CNT, Pd₉₀Au₁₀/CNT, Pd₉₀Au₁₀/CNT, Pd₇₀Au₃₀/CNT, Pd₅₀Au₅₀/CNT, and Pd₄₀Au₆₀/CNT catalysts. These catalysts are characterized via advanced surface analytical techniques namely N₂ adsortion-desoprtion measurements,X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM). The characterization results revealed that Pd₉₀Au₁₀/CNT has 205.42 m²/g and 1.18 cm³/g BET surface area (m²/g) and pore volume (cm³/g), respectively. On the other hand, XRD and XPS results revealed that the electronic state of Pd₉₀Au₁₀/CNT catalyst changed by Au addition to Pd. TEM and HRTEM and elemental mapping results reveal that Pd and Au is homogeneously dispersed and alloying of Pd and Au is clearly observed, in agreement with the XRD and XPS results. Ethanol electrooxidation measurements in alkaline environment are performed by Cyclic Voltammetry (CV), Chronoamperometry (CA), Electrochemical impedance spectroscop (EIS) techniques. Pd₉₀Au₁₀/CNT displayed the highest specific and mass activity. The synergistic effect between Pd and Au at optimized metal ratio was utilized to obtain an improvement in specific activity. Furthermore, Pd₉₀Au₁₀/CNT showed the lowest charge transfer resistance (R_ct) and a long term stability. As a result, it is clear that PdAu catalyst is a promising catalyst for Alkaline Direct Ethanol Fuel Cells.     

The studies of performance of the Au electrode modified by Zn as the anode electrocatalyst of direct borohydride fuel cell

The carbon supported Au-base electrocatalysts (Au_(1−x)Zn_x/C, 0 ≤ x < 1) modified by Zn were synthesized by reverse microemulsion method and employed as anode electrocatalysts of direct borohydride fuel cell (DBFC). The physical and electrochemical properties were investigated by energy dispersive X-ray (EDX), X-ray diffraction (XRD), transmission electron microscopy (TEM), cyclic voltammetry (CV), chronopotentiometry and fuel cell test. The results showed that the morphologies of Au_(1−x)Zn_x nanoparticles all were uniformly spherical no matter what Zn content changed, and the average particle size of Au_(1−x)Zn_x bimetallics varied from 3 to 6 nm. The electrochemical measurements revealed that the Au_(1−x)Zn_x/C electrocatalysts showed no activity toward the NaBH₄ hydrolysis reaction and obviously improved the catalytic activity of borohydride oxidation. Compared with Au/C anode electrocatalyst, the stability of DBFC using the Au_0.65Zn_0.35/C as anode electrocatalyst was apparently improved, and the maximum power density of 39.5 mW cm⁻² was obtained at 20 °C.     

Synthesis of Cu@FeCo core–shell nanoparticles for the catalytic hydrolysis of ammonia borane

Non-noble Cu@FeCo core–shell nanoparticles (NPs) containing Cu cores and FeCo shells have been successfully in situ synthesized via a facile chemical reduction method. The NPs exerted composition-dependent activities towards the catalytic hydrolysis of ammonia borane (NH₃BH₃, AB). Among them, the Cu_0.3@Fe_0.1Co_0.6 NPs showed the best catalytic activity, with which the max hydrogen generation rate of AB can reach to 6674.2 mL min⁻¹ g⁻¹ at 298 K. Kinetic studies demonstrated that the hydrolysis of AB catalysed by Cu_0.3@Fe_0.1Co_0.6 NPs was the first order with respect to the catalyst concentration. The activation energy (Ea) was calculated to be 38.75 kJ mol⁻¹. Furthermore, the TOF value (mol of H₂. (mol of catalyst. min)⁻¹) of Cu_0.3@Fe_0.1Co_0.6 NPs was 10.5, which was one of the best catalysts in the previous reports. The enhanced catalytic activity was largely attributed to the preferable synergistic effect of Cu, Fe and Co in the special core–shell structured NPs.     

In situ synthesized Fe–Co/C nano-alloys as catalysts for the hydrolysis of ammonia borane

Composite catalysts Fe_0.3Co_0.7-doped carbon aerogel have been in situ synthesized by chemical reduction method and successfully employed in the hydrolysis of NH₃BH₃ (AB) at room temperature. The mass percent of the doped Fe_0.3Co_0.7 alloys can reach to the maximum value of 40 wt%. The prepared catalysts exhibit excellent catalytic activity, especially for the specimen of 40 wt% Fe_0.3Co_0.7/C, which shows high catalytic activity and long durability. Its maximum hydrogen generation rate is as high as 13,695.6 ml min⁻¹ g⁻¹ at 298 K and the activation energy is only 20.83 kJ mol⁻¹. Besides, this catalyst possesses preferable cycling stability at room temperature. The low cost, high catalytic activity and enhanced cycling stability can make it have a bright future in the application field of fuel chemistry.     

Catalytic activities of Ag/C decorated with small amounts of Au and Pt for glycerol oxidation

The two-step decoration of the Ag nanoparticles supported on carbon black (Ag/C) with Au and Pt, the electrooxidation of glycerol on the Pt/Au/Ag/C catalysts in alkaline solution, and the effect of the amounts of Au and Pt on the catalytic activity of Pt/Au/Ag/C are investigated. The decoration of Ag/C is performed by electrochemically depositing a small amount of Au and then Pt on Ag/C, and the Pt_x/Au_y/Ag₁₀₀/C catalysts with different x:y:100 ratios (0.15 ≤ x ≤ 1.9 and 0.2 ≤ y ≤ 1.5) are obtained. Physical and electrochemical characterizations reveal that small parts of the Ag surfaces are covered by the deposited Au and Pt. Pt_x/Au_y/Ag₁₀₀/C mainly shows Pt-relevant behaviors in glycerol oxidation, and Pt_1.3/Au_y/Ag₁₀₀/C exhibits high catalytic activities. The results reveal that the surface decoration is a useful method of fabricating efficient ternary catalysts at low cost.     

Carbon-supported Ni3B nanoparticles as catalysts for hydrogen generation from hydrolysis of ammonia borane

We report the preparation of Ni₃B and carbon-supported Ni₃B (denoted as Ni₃B/C) nanoparticles, and their catalytic performance for hydrogen generation from hydrolytic dehydrogenation of ammonia borane (NH₃BH₃, AB). Ni₃B and Ni₃B/C were prepared via a chemical reduction and crystallization in tetraethylene glycol solution. The obtained Ni₃B catalysts are in well-defined crystalline state and Ni₃B/C catalysts have a high dispersion in the carbon. The hydrogen generation measurement shows that the carbon-supported Ni₃B presents enhanced catalyst activity during hydrolytic dehydrogenation of AB. Among the as-prepared Ni₃B/C catalysts, Ni₃B/C with 34.25 wt% Ni₃B loading displays the best catalytic activity, delivering a high hydrogen release rate of 1168 mL min⁻¹ g⁻¹ and the lower activation energy of 46.27 kJ mol⁻¹. The kinetic results show that the hydrolysis is a first-order reaction in catalyst concentration, while it is a zero-order in AB concentration. Furthermore, the Ni₃B/C is a recyclable catalyst under mild reaction conditions, indicating that the carbon-supported Ni₃B is a promising catalyst for AB hydrolytic dehydrogenation.     

Preferential CO oxidation over Au/ZnO and Au/ZnO–Fe2O3 catalysts prepared by photodeposition

Preferential CO oxidation in a H₂-rich stream was studied over Au/ZnO and Au/ZnO–Fe₂O₃ catalysts prepared by photodeposition under UV–vis light. The high catalytic activities of both Au/ZnO and Au/ZnO–Fe₂O₃ catalysts are presented over a temperature range of 30–130 °C. TEM results revealed that the average particle size of Au over the Au/ZnO and Au/ZnO–Fe₂O₃ catalysts, is in the range of 3–5 nm. Moreover, DR/UV–vis spectra showed that the prepared catalysts contained Au^δ+ and Au⁰ (active sites for the PROX reaction) on the catalyst support. Based on the experiment observations, it can be concluded that the catalysts prepared by a photodeposition exhibited excellent catalytic activity, even when both CO₂ and H₂O were added to the simulated stream.     

Hydrogen production from sodium borohydride originated compounds: Fabrication of electrospun nano-crystalline Co3O4 catalyst and its activity

Electrospun nanofibers are prepared through electrospinning followed by post-treatment and preferred to use in catalytic applications. The electrospinning provides advantages for active catalysts design based on activity profiles and features of catalyst. In the present study, we fabricated nano-crystalline cobalt oxide (Co₃O₄) catalyst by electrospinning technique followed by thermal conditioning. Polyacrylonitrile (PAN) based Co as-spun mats (Co/NMs) with homogeneous diameter were prepared by electrospinnig process under several conditions as applied voltage (15–25 kV), working distance (5–7.5 cm) with the feed rate of 1 ml min⁻¹. The calcination process as a post-treatment was applied at different temperatures (232 °C, 289 °C and 450 °C) to obtain electrospun nano-crystalline Co₃O₄ catalyst. Co/NMs catalysts were characterized by XRD, SEM, TEM, XPS, FT-IR, TG/DTG, and ICP-MS techniques. The parametrically study was performed for evaluating the hydrogen production activity of catalyst from sodium borohydride (NaBH₄, SBH) and its originated compounds as ammonia borane (NH₃BH₃, AB) and methyl-amine borane (CH₃NH₂BH₃, MeAB). The relation between the internal-external properties and catalytic activities of catalysts for hydrogen production was investigated. The beadless Co/NMs-1 catalyst with homogeneous diameter was obtained under electrospinnig process conditions at 15 kV applied voltage and 7.5 cm working distance. All catalysts showed activity for hydrogen production, also the significant effect of post treatment process was observed on the catalytic activity as given order: Co/NMs-1₄₅₀ > Co/NMs-1₂₈₉ > Co/NMs-1 > Co/NMs-1₂₃₂. Furthermore, mesoporous Co₃O₄ cubic crystals (26 nm) in fibrous architecture was prepared by 450 °C-post-treatment. Hydrogen production rates were recorded at 60 °C as 2.08, 2.20, and 6.39 l H₂.g_cat⁻¹min⁻¹ for NaBH₄, CH₃NH₂BH₃, and NH₃BH₃, respectively.     

Borohydride electrochemical oxidation on carbon-supported Pt-modified Au nanoparticles

The carbon-supported Pt-modified Au nanoparticles were prepared by two different chemical reduction processes, the simultaneous chemical reduction of Pt and Au on carbon process (A-AuPt/C) and the successive reduction of Au then Pt (B-AuPt/C) on carbon process. These two catalysts were investigated as the anode catalysts for a direct borohydride fuel cell (DBFC) and Au nanoparticles on carbon (Au/C) were also prepared for comparison. The DBFC with B-AuPt/C as the anode catalyst shows the best anode and fuel cell performance. The maximum power density with the B-AuPt/C catalyst is 112 mW cm⁻² at 40 °C, compared to 97 mW cm⁻² for A-AuPt/C and 65 mW cm⁻² for Au/C. In addition, the DBFC with the B-AuPt/C catalyst shows the best fuel utilization with a maximum apparent number of electrons (N_app) equal to 6.4 in 1 M NaBH₄ and 7.2 in 0.5 M NaBH₄ as compared to the value of N_app of 8 for complete utilization of borohydride.     

A quaternary ammonium grafted poly vinyl benzyl chloride membrane for alkaline anion exchange membrane water electrolysers with no-noble-metal catalysts

This work reported an alkaline anion exchange membrane water electrolyser (AAEMWE) without noble metal as the catalyst. Methylated melamine grafted poly vinyl benzyl chloride (mm-qPVBz/Cl⁻) was synthesized and cast as the membrane. The conductivity of this hydroxide ion exchange membrane increased from 1.6 × 10⁻² S cm⁻¹ to 2.7 × 10⁻² S cm⁻¹ when the temperature was increased from 25 °C to 60 °C. Membranes were examined using TEM. The oxygen evolution catalyst used was based on Cu_0.7Co_2.3O₄ particle 20–30 nm in size, synthesized through a thermal decomposition method. A membrane electrode assembly was prepared with the resultant membrane as electrolyte, the Cu_0.7Co_2.3O₄ nano-particles as the anode catalyst and Ni nano-powders as the hydrogen evolution catalyst. SEM observations showed that the catalysts were well dispersed on the electrodes. The polarization curves exhibited onset voltages for water electrolysis of around 1.5 V. The MEA polarisation in deionised water exhibited voltages of 2.19 V, 2.05 V, 1.99 V at a current density of 100 mA cm⁻² at temperatures of 25 °C, 40 °C and 55 °C respectively.     

Dehydrogenation characteristics of ammonia borane via boron-based catalysts (Co–B,Ni–B,Cu–B) under different hydrolysis conditions

In the present study, dehydrogenation characteristics of ammonia borane (NH₃BH₃) catalyzed via boron-based catalysts under different hydrolysis conditions were investigated. A series of boron-based catalysts (Co_1−x–B_x, Ni_1−x–B_x, and Cu_1−x–B_x, x: 0.25, 0.50, 0.75) were prepared by sol–gel method. Gels were calcinated at different temperatures (250 °C, 350 °C, and 450 °C) in order to obtain the boron-based catalysts. XRD characterizations revealed that Co–B, Ni–B, and Cu–B crystalline structures were formed during calcination at 450 °C. Hydrogen generation measurements were performed in order to determine the optimum composition of the boron-based catalyst. The maximum hydrogen generation rates were 7607 ml min⁻¹ gcat⁻¹, 3869 ml min⁻¹ gcat⁻¹ and 1178 ml min⁻¹ gcat⁻¹ for Co_0.75B_0.25, Ni_0.75B_0.25 and Cu_0.75B_0.25, respectively. Furthermore, the hydrolysis of NH₃BH₃ was performed at 20 °C, 40 °C, 60 °C and 80 °C under magnetic stirring (750 rpm), ultrasonic irradiation and non-stirring in order to determine how these parameters effect hydrolysis. Activation energies (E_a) were calculated by evaluation of the kinetic data. Under ultrasonic irradiation, the E_a in the presence of Co_0.75B_0.25, Ni_0.75B_0.25 and Cu_0.75B_0.25 were 40.85 kJ mol⁻¹, 43.19 kJ mol⁻¹ and 48.74 kJ mol⁻¹, respectively, which compares favorably with results reported in the literature. Thus, the catalytic activities of the boron-based catalysts were found to be Cu < Ni < Co and the best reaction condition for the catalytic hydrolysis of NH₃BH₃ was determined to be non-stirring < magnetic stirring < ultrasonic irradiation.     

Bimetallic RuCo and RuCu catalysts supported on γ-Al2O3. A comparative study of their activity in hydrolysis of ammonia-borane

Bimetallic-based RuCo and RuCu catalysts, supported on γ-Al₂O₃ (1.5 wt% Ru as theoretical value), were synthesized by polyol method. Ru, Co, and Cu acetylacetonates were used as precursors and ethylene glycol as reducing agent. The as-synthesized catalysts were characterized by SEM, TEM, XRD and XPS, and tested in ammonia-borane (NH₃BH₃) hydrolytic dehydrogenation at variable amount of catalyst (10-30 wt%), concentration of NH₃BH₃ (1.0-0.65 M), and temperatures (50-65 °C). The reactions were monitored by volumetric (inverted burette) and spectroscopic methods (¹¹B and ¹¹B{¹H} NMR). It was found that the best bimetallic catalysts are those having a molar ratio Ru:Co and Ru:Cu of 1:1 such as RuCo > RuCu ∼ Ru. They, i.e. RuCo and RuCu, consist of nanosized spherical particles of Ru⁰Co(OH)₂ and Ru⁰Cu⁰, respectively. Kinetic investigation highlights similar rate laws with activation energies of 47 kJ mol⁻¹ and 52 kJ mol⁻¹, respectively, and, for both, reaction orders of 1 versus both the NH₃BH₃ and the catalytic free sites concentrations. ¹¹B and ¹¹B{¹H} NMR investigation confirmed (i) a more effective NH₃BH₃ hydrolytic dehydrogenation in the presence of RuCo catalyst even though a loss of activity after the first run was observed for both catalysts, and (ii) a rapid NH₃BH₃ hydrolysis with initial formation of B(OH)₄⁻, which besides favors equilibriums of formation of polyborates. These results are reported and the reaction mechanism discussed herein.     

Improved catalytic performance of metal oxide catalysts fabricated with electrospinning in ammonia borane methanolysis for hydrogen production

Electrospun Ni and Cu metal oxide catalysts are successfully synthesized through electrospinning and conventional sol-gel methods to show advantages of electrospinning on catalytic performance in ammonia borane (NH₃BH₃) methanolysis for hydrogen production. An experimental assessment is presented by the characterization of interior and exterior properties of all catalysts and their catalytic activity towards NH₃BH₃ methanolysis. The systematic studies are performed in order to figure out of kinetic interpretation. Catalytic NH₃BH₃ methanolysis reactions are carried out at different catalyst amounts (5–15 mg), initial NH₃BH₃ concentrations (0.36–6.0 M) and temperatures (20–50 °C). Thanks to the higher pore volume/S_BET ratio, fiber type nanostructured Cu oxide catalyst exhibits the highest catalytic activity compared with sol-gel prepared ones. The results of kinetic studies show that the fiber type Cu oxide catalyst catalyzed methanolysis of NH₃BH₃ and follows the first order reaction kinetic model with 35 kJ mol⁻¹ activation energy value.