Ordered mesoporous Ni/Silica-carbon as an efficient and stable catalyst for CO2 reforming of methane

Ordered mesoporous silica-carbon (MSC) were used as supports of Ni based catalysts for dry reforming of methane (DRM) reaction. The effects of preparation method and precipitant on the catalysts are investigated. The physical and chemical properties are discussed based on the H₂-TPR, FTIR, XRD, TEM, H₂-TPD and N₂ adsorption/desorption characterization. It is found that the preparation method and choice of precipitants affect the catalysts significantly in terms of the properties and catalytic performance in DRM reaction. In detail, the catalysts prepared by the precipitation method show more highly dispersed Ni particles and further better catalytic activity than the impregnated catalyst. That is attributed to the forming Ni₃Si₂O₅(OH)₄ nanoflakes in the catalyst precursors with the existence of alkaline precipitants. And this Ni₃Si₂O₅(OH)₄ species bind the support more tightly than NiO in the impregnated Ni/MSC catalyst. Moreover, the choice of precipitants also influences the form of Ni₃Si₂O₅(OH)₄ species in the catalysts. Specially, the strong electrolytic capacity of NaOH gives the most Ni₃Si₂O₅(OH)₄ nanoflakes formed in Ni-MSC-1 catalyst, which results in the most highly Ni dispersity and further highest catalytic activity. Besides, the strong interaction between the Ni₃Si₂O₅(OH)₄ species and support are also advantageous to the resist sintering and formation of carbon deposition, that is related to the good catalytic stability of catalysts.     

Influence of CaO precursor on CO2 capture performance and sorption-enhanced steam ethanol reforming

This work presents the effect of calcium and carbonate precursors on properties of CaCO₃. The synthetic CaCO₃ samples were transformed into CaO and tested their application to high-temperature CO₂ capture. Four different sorbent precursors were investigated in this work, including calcium chloride (CaCl₂) and calcium acetate (CaAc₂) as calcium precursor, and sodium carbonate (Na₂CO₃) and urea (CO(NH₂)₂) as carbonate precursor. The results show that both calcium and carbonate precursors affect morphologies of CaCO₃; CaCO_3,Cl-Urea, and CaCO_3,Cl-Na have calcite phase, whereas mixed-phases of calcite (30%) and vaterite (70%) are observed with CaCO_3,Ac-Na, and aragonite is found with CaCO_3,Ac-Urea. CaCO_3,Cl-Na exhibits small cubic (rhombohedral) particle, CaCO_3,Cl-Urea possesses spherical particle with rough surface, CaCO_3,Ac-Na has spherical-like morphology with smooth surface, and CaCO_3,Ac-Urea possesses aggregated form of CaCO₃ particles. For application to CO₂ capture, CaO derived from CaCO_3,Ac-Urea provides the highest CaO conversion of 80% at 700 °C. The synthetic CaO-based sorbents were further incorporated with nickel oxide to form one-body bi-functional catalysts for H₂ production from sorption-enhanced steam ethanol reforming. The results show that 87%H₂ purity could be obtained with pre-breakthrough period of 60 min. Sorbent reactivity can be maintained the production of H₂ for at least 10 consecutive cycle tests.     

Effect of CaO hydration and carbonation on the hydrogen production from sorption enhanced water gas shift reaction

Sorption enhanced water gas shift reaction (SEWGS) based on calcium looping is an emerging technology for hydrogen production and CO₂ capture. SEWGS involves mainly two reactions, the catalytic WGS reaction and the bulk carbonation of CaO with CO₂, and the solid product is CaCO₃, and the Ca(OH)₂ may be formed from the reaction of CaO with H₂O with the presence of steam in gas phase. The effect of Ca(OH)₂ and CaCO₃ on the catalytic WGS reaction and carbonation reaction was studied in a fluidized bed reactor. It was found that the hydrated sorbent and CaCO₃ did not show any catalytic reactivity toward WGS reaction at 400 °C. When the temperature was increased to 500 °C and 600 °C, the catalytic reactivity of hydrated sorbent was recovered partially, but this will depend on the steam fraction in gas phase, the recovery of fresh CaO surface from dehydration of Ca(OH)₂ may be the reason of catalytic reactivity recovery. CaCO₃ can catalyze the WGS reaction at the high-temperature (>600 °C), this may due to the CaCO₃ decomposition and recarbonation processes in which the CaO is transiently formed. The possible mechanism was discussed.     

Effect of kaolin addition on ash characteristics of palm empty fruit bunch (EFB) upon combustion

Palm empty fruit bunch (EFB), a by-product of the palm oil industry, is being recognized as one of the most potential kinds of biomass for energy production in Thailand. However, it has been reported that, in combusting EFB in boilers, some compounds evolving from abundant alkali metals in EFB into gas-phase condense and deposit on low-temperature surfaces of heat exchange equipment, causing fouling and corrosion problems. To come up with a solution to impede the deposition, kaolin, which is abundant in kaolinite (Al₂Si₂O₅(OH)₄), is employed to capture the alkali metal vapours eluding from the combustion region. The experiments were designed to simulate the combustion situations that may take place when kaolin is utilized in two different approaches: premixing of kaolin with EFB prior to combustion and gas-phase reaction of volatiles from EFB with kaolin. The amounts of kaolin used were 8% and 16% by weight based on dry weight of EFB, which were equivalent to one and two times of the theoretical kaolin requirement to capture all potassium originally present in the EFB. The furnace temperatures used for EFB combustion were 700–900 °C and ashes were analyzed by XRF and XRD. The results revealed that, under the kaolin premixing condition, 8% kaolin addition was sufficient to capture the potassium compounds at low temperature, i.e. 700 and 800 °C. However, when the temperature was increased to 900 °C, 16% kaolin addition was needed to completely capture the potassium compounds. The results from gas-phase experiments showed that kaolin can capture volatile potassium at maximum 25% at 900 °C. The XRD results showed, for both experimental cases, the evidence of formation of the high melting temperature potassium-alumino-silicates, which confirmed the reaction of potassium compounds with kaolin. The study also suggests that the premixing method is better than the other because of its higher overall capture efficiency.     

Influence of AlCl3 and oxidant catalysts on hydrogen production from the supercritical water gasification of dewatered sewage sludge and model compounds

Hydrogen has attracted significant attention as a clean energy source. Supercritical water gasification (SCWG) technology can produce hydrogen-rich gas while also disposing of sludge. The hydrogen yield from the SCWG of sludge is greatly increased when catalyzed by AlCl₃. In this paper, a combined catalyst based on AlCl₃ was proposed to further increase the hydrogen yield of SCWG of dewatered sewage sludge (DSS). Analysis of the products from catalytic gasified of DSS and its model compounds were used to propose a catalytic mechanism and reaction pathway of the catalytic SCWG of DSS. Among the combined catalysts used for the SCWG of DSS, 10 wt% AlCl₃–H₂O₂ (mass ratio 8:2) had the best hydrogen production effect, and the hydrogen yield reached 8.88 mol/kg organic matter. This was 14% higher than when catalyzed by 10 wt% AlCl₃. During catalysis with AlCl₃, Al³⁺ reacted with OH⁻ in water and precipitated as Al(OH)₃, which produced an acidic environment in the liquid product. Al(OH)₃ dehydrated to form an AlO(OH) and deposited in the solid product. A small amount of H₂O₂ promoted the steam reforming reaction of organic matter in DSS, which increased the hydrogen yield. H₂O₂ further promoted the hydrogen yield in an acidic environment. The catalytic effect of AlCl₃ was unaffected by H₂O₂. The H⁺ generated by AlCl₃ during catalysis promoted H₂O₂ to further depolymerized organic matter (such as humic substances) in DSS, so that AlCl₃–H₂O₂ catalyzed the SCWG of DSS to further increase the hydrogen yield. The order of hydrogen yield catalyzed by AlCl₃–H₂O₂ was guaiacol > humic acid > glycerol > alanine > glucose. Compared with AlCl₃, AlCl₃–H₂O₂ reduced the hydrogen yield of glucose by nearly 20% and increased the hydrogen yield of humic acid by about 17% (25.81 mol/kg feed).     

Effect of impurities and moisture on lithium bisoxalatoborate (LiBOB) electrolyte performance in lithium-ion cells

Electrolytes containing LiB(C₂O₄)₂ (LiBOB) salts are of increasing interest for lithium-ion cells for several reasons that include their ability to form a stable solid electrolyte interphase on graphite electrodes. However, cells containing these electrolytes often show inconsistent performance because of impurities in the LiBOB salt. In this work we compare cycling and impedance data from cells containing electrolytes with LiBOB that was obtained commercially and LiBOB purified by a rigorous recrystallization procedure. We relate the difference in performance to a lithium oxalate impurity that may be a residual from the salt manufacturing process. We also examine the reaction of LiBOB with water to determine the effect of salt storage in high-humidity environments. Although LiBOB electrolytes containing trace amounts (∼100 ppm) of moisture appear relatively stable, higher moisture contents (∼1 wt%) lead to observable salt decomposition resulting in the generation of B(C₂O₄)(OH) and LiB(C₂O₄)(OH)₂ compounds that do not dissolve in typical carbonate solutions and impair lithium-ion cell performance.     

Cyclic CO2 capture performance of carbide slag

The carbonate looping process is a promising technology for CO₂ capture. The decay of sorbents reactivity over multiple cycles is an obstacle for realizing the carbonate looping process. In this work, the reactivity and stability of carbide slag for CO₂ capture have been examined. The results show that carbide slag exhibits superior CO₂ capture performance even at severe calcination temperatures in comparison with limestones, shells, pure CaCO₃, and Ca(OH)₂. X-ray diffraction analysis shows that there is mayenite (Ca₁₂Al₁₄O₃₃) formed in the calcination step for carbide slag, which is the main reason for its high stability in the carbonate looping process.     

Hierarchitecture Co2(OH)3Cl@FeCo2O4 composite as a novel and high-performance electrode material applied in supercapacitor

One-step hydrothermal reaction has successfully been used to prepared three-dimensional hierarchitecture Co₂(OH)₃Cl@FeCo₂O₄ composite without any annealing treatment. The samples are investigated to confirm the crystal structure, elemental composition, morphology structure and electrochemical performance. The results show the sample has a three-dimensional hierarchitecture that nanoblocks are assembled with nanoparticles. And the specific surface area is 87.5 m² g⁻¹ and the total pore volume is 0.17 cm³ g⁻¹. Meanwhile, the composite shows a high specific capacitance of 1110.0 F·g⁻¹ at 1 A·g⁻¹ and great cycling stability with 98.8% capacitance retention after 3000 cycles. To evaluate the electrochemical performances, the results are used to compare with the Co₂(OH)₃Cl and FeCo₂O₄ nanomaterials, indicating a higher capacitance and longer cycle stability shown by the as-synthesized sample. The as-synthesized Co₂(OH)₃Cl@FeCo₂O₄ composite has an outstanding electrochemical performance, predicting an enormous potential and promising future as a novel electrode material applied in supercapacitor.     

HCl Dry Removal with Modified Ca-Based Sorbents at Moderate to High Temperatures

Modified Ca-based sorbents were obtained by adding sodium alkali into Ca(OH)2 and CaCO3. Reactive properties of modified Ca-based sorbents with acidic gases were investigated through reacting with gaseous HC1 at 450-760℃, and SEM and XRD technologies were adopted to get information on the reaction mechanism. Experimental data showed that HC1 dry removal efficiencies increased with temperature before 700℃ for all of the investigated sorbents, and there existed improved sorbents that corresponded to the highest removal efficiencies under the similar conditions. SEM photographs exhibited morphology difference between original and improved sorbents both before and after the reaction; and displayed that improved sorbents formed more porous product layers than original sorbents especially at higher temperature when product sintering became heavier, which is favorable to HC1 dry removal. XRD analysis showed that (1) improved Ca(OH)2 and CaCO3 were less crystalline than original lime and limestone; (2) the re     

Which is the better catalyst for CO2 methanation – Nanotubular or supported Ni-phyllosilicate?

In order to investigate effects of morphology and crystalline phase of different Ni-phyllosilicate catalysts on the catalytic performance for CO₂ methanation, nanotubular Ni-phyllosilicate and MCM-41 supported Ni-phyllosilicate were synthesized through hydrothermal reaction of sodium silicate or MCM-41 with nickel nitrate. On one hand, nanosheets attributing to 2:1 type nickel phyllosilicate (Ni₃Si₄O₁₀(OH)₂·5H₂O) were uniformly grown on the surface of MCM-41 spheres to form the MCM-41 supported Ni-phyllosilicate (Ni/M). On the other hand, 1:1 type Ni-phyllosilicate with nanotubular morphology (Ni/N) was synthesized through the reaction of Na₂SiO₃ and nickel nitrate. After a series of tests and characterizations, it was found that Ni/N exhibited low thermal stability and poor anti-sintering property, leading to poor catalytic activity for CO₂ methanation. On the contrary, Ni/M was very stable, which obtained unchanged morphology and fine Ni particles after 750^oC-reduction, resulting in high catalytic activity and long-term stability for CO₂ methanation. In all, morphology and crystalline phase of Ni-phyllosilicate obviously affected catalytic performance, and the supported Ni-phyllosilicate catalyst was much better than the nanotubular Ni-phyllosilicate for CO₂ methanation in this work.     

Hydrothermal synthesis of CuV2O6 supported on mesoporous SiO2 as SO3 decomposition catalysts for solar thermochemical hydrogen production

Hydrothermal synthesis of CuV₂O₆ supported on 3-D ordered mesoporous SiO₂ (CuV/SiO₂) was studied to evaluate the catalytic activity for SO₃ decomposition, which is a key step in solar thermochemical hydrogen production. A composite oxide hydrate, Cu₃O(V₂O₇)·H₂O, and an oxide hydroxide hydrate, Cu₃(OH)₂V₂O₇·(H₂O)₂, were formed at lower hydrothermal temperatures (≤200 °C). The oxide hydrate phase mainly yielded Cu₂V₂O₇ after calcination at 600 °C in air. By contrast, the hydrothermal synthesis at 250 °C (CuV/SiO₂@250) directly crystallized CuV₂O₆ from the oxide hydroxide hydrate, although its very large particle size (∼5 μm) is not suitable for the catalytic application. The SO₃ decomposition activity measured at 600 °C was associated with the yield as well as the dispersion of CuV₂O₆, giving rise to the maximum for the hydrothermal synthesis at 200 °C. CuV/SiO₂@250 achieved the highest catalytic activity at the reaction temperature of 650 °C, because the melting phase of CuV₂O₆ penetrated mesoporous SiO₂ and thus improved the dispersion of the active phase.     

Effects of headspace fraction and aqueous alkalinity on subcritical hydrothermal gasification of cellulose

In order to better understand the pathways of hydrothermal gasification of cellulose, the effect of headspace fraction and alkalinity on the hydrothermal gasification of cellulose has been studied at 315 °C in the presence of Pt/Al₂O₃ as catalyst. It was found that regardless of alkalinity the headspace fraction had a large impact on gasification yield, with larger headspace fractions resulting in considerably more gas product. Without the addition of sodium carbonate, the effect of headspace fraction became more pronounced, with gas increasing by approximately a factor of forty from the lowest to highest headspace fraction. On the other hand, for the same residence time the addition of sodium carbonate co-catalyst dampened the magnitude of the effect, to a factor of 2.5 and 1.5, for 50 and 100 mM sodium carbonate solutions, respectively. These results indicated that the headspace fraction affected the phase behaviour, and that this altered the pathway of the cellulose decomposition. While furfural alcohol was the major product obtained with a 49% headspace fraction, it was effectively suppressed by using 78% or greater headspace fractions. Based on the effects of phase behaviour and previous literature, the reduced effect occurring upon the addition of sodium carbonate may relate to catalysis of the Lobry de-bruyn Van Eckenstein transform to produce lactic acid rather than intermediates proceeding through glycolaldehyde.     

Pyroxene control of H2 production and carbon storage during water-peridotite-CO2 hydrothermal reactions

Strategies of H₂ production and CO₂ mineralization were combined through olivine [(Mg,Fe)₂SiO₄] serpentinization and carbonation in a CO₂-rich hydrothermal system. However, natural mantle peridotites commonly contain not only olivine but also orthopyroxene and/or clinopyroxene, which have effects that are not well understood. The present study investigated the reactions in H₂O-olivine/orthopyroxene-CO₂ systems by performing hydrothermal experiments in 0.5 M NaHCO₃ solutions at 300 °C and 10 MPa.The yields of H₂ and HCOOH initially were first suppressed in the presence of orthopyroxene; however, after orthopyroxene consumption, the rate of H₂ production increased significantly. H₂ yield increased to 348.3 mmol/kg_mineral in 120 h with the presence of 20 wt% orthopyroxene at the beginning of the reaction. The initial suppression of H₂ generation was due to incorporation of more Fe(II) into serpentine [(Mg,Fe)₃Si₂O₅(OH)₄] in the high SiO_2(aq) concentration system. The presence of orthopyroxene also dramatically accelerated serpentine formation. In contrast, magnesite [(Mg,Fe)CO₃] formation was inhibited upon addition of orthopyroxene, which also contributed to the release of Fe(II). Therefore, peridotite containing ≤20 wt% of pyroxenes is more suitable for long-term H₂ production than pure olivine. When considering the reaction output of a water-peridotite-CO₂ system, controlling the percentage of pyroxenes in the starting mineral may be more important than expected.     

System for hydrogen production by water photoelectrolysis with p-Si and p-InP photocathodes

A new photoelectrochemical system based on semiconductor photocathodes (p-Si, p-InP) and an electron carrier (mediator) is proposed. Aqueous solutions of heteropolyacids (HPA): H₄(PMo₁₂O₄₂), H₈(SiW₁₂O₄₂), H₇(PW₁₂O₄₂) and H₈(SiMo₁₂O₄₂) were examined for use as mediators. The electrons generated in the semiconductor upon illumination reduce HPA. This reaction proceeds at a lower overvoltage than the direct hydrogen photoevolution from aqueous acid solution. The mediator reduction on the photocathode is followed by a homogeneous dark chemical reaction between the reduced mediator and water, which results in hydrogen evolution. The catalytic activity of the photocathodes investigated towards electroreduction of HPA increases after deposition of platinum traces on the working surface of the electrode.     

Effect of CO2 atmosphere on Ca-containing mineral transformation behaviors during a Ca dominated coal co-firing with a Si/Al dominated coal in oxy-fuel condition

Coal blending is an effective method to reduce the slagging tendency. The mineral transformation within blended coal ashes has an important influence on the slagging behaviors, which have been well studied under conventional air-fuel condition. Oxy-fuel combustion is recognized as one of the most promising CO₂ reduction technologies. However, the mineral transformation within blended coal ashes in oxy-fuel condition has yet to be fully understood. This work is aimed to comprehensively study the influence of CO₂ atmosphere on Ca-containing mineral transformation behaviors during a Ca dominated coal co-firing with a Si/Al dominated coal in O₂/CO₂ condition by TG-DSC, XRD and HSC simulation. These results show that the atmosphere significantly affects on the transformation of Ca-containing mineral and the final existing form of Ca in the blended coal ashes. When the high content Ca coal is blended with the high content Al/Si coal in the O₂/CO₂ atmosphere, the CO₂ promotes the transformation of Ca into CaCO₃ and Ca under low temperature mainly exists in the form of CaCO₃ (little CaSO₄) in the blended coal ashes. CaCO₃ under high temperature is decomposed to produce highly active CaO, and CaO reacts with Al/Si to form the low melting point minerals, which may aggravate the slagging tendency. The present study can provide useful information to reduce the slagging behavior of the blended coals in the O₂/CO₂ atmosphere.     

Photocatalytic H2 evolution from NaCl saltwater over ZnS1−x−0.5yOx(OH)y-ZnO under visible light irradiation

Photocatalytic hydrogen production was investigated over ZnS_1−x−0.5yO_x(OH)_y-ZnO using sulfide ion (Na₂S-Na₂SO₃) as an electron donor from NaCl saltwater. NaCl can affect markedly the activity for photocatalytic hydrogen production, depending on NaCl concentration. When NaCl concentration is lower, the activity is lower than that in pure water, whereas when NaCl concentration is higher, the activity is higher than that in pure water. NaCl decreases not only the surface charge of ZnS_1−x−0.5yO_x(OH)_y-ZnO but also the surface hydration. When ZnS_1−x−0.5yO_x(OH)_y-ZnO was impregnated with the electron donor (Na₂S-Na₂SO₃), ZnO was transformed partly into ZnS. The impregnated ZnS_1−x−0.5yO_x(OH)_y-ZnO exhibits higher activity than the non-impregnated one. The possible mechanisms were discussed.     

Construction of amorphous CoFeOx(OH)y/MoS2/CP electrode for superior OER performance

Design and direct construction of oxygen evolution reaction (OER) catalyst-based electrode is an efficient route to improve the water splitting reaction. Herein, we proposed a facile route to synthesize and load the composite of amorphous CoFe oxyhydroxide (CoFeO_x(OH)_y) and MoS₂ on the carbon paper by combining a hydrothermal and an electrodeposition process. CoFeO_x(OH)_y has a special feature of long-range disorder (amorphous phase) and short-range order (crystal phase), which greatly improves the OER catalytic performance of the hybrids. In virtue of the synergistic effect of CoFeO_x(OH)_y and MoS₂, an improved electronic coupling effect occurs, which increases the oxidation state of Co and Fe, and thus enhances OER activity. As-synthesized CoFeO_x(OH)_y/MoS₂/CP (CFOMS/CP) electrode affords excellent electrocatalytic activity and good electrochemical OER stability: A small Tafel slope of 37.9 mV dec^?1 (vs. 62.1 mV dec^?1 for CoFeO_x(OH)_y/CP, 120.2 mV dec^?1 for RuO₂/CP) and low overpotential 242 mV at 10 mA cm^?2 (vs. 263 mV for CoFeO_x(OH)_y/CP, 317 mV for RuO₂/CP), as well as a stable running for 25 h.     

Synthesis of lawn-like NiS2 nanowires on carbon fiber paper as bifunctional electrode for water splitting

a low-cost electrode with lawn-like NiS₂ nanowire arrays on flexible carbon fiber paper was synthesized, for the first time, via sulfurization of Ni₂(CO₃)(OH)₂ precursor. And the performance of this electrode as a bifunctional electrocatalyst toward both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) was evaluated. It shows that NiS₂ NWs/CFP requires small overpotentials of 165 mV for HER and 246 mV for OER, respectively, to deliver the current density of 10 mA cm^?2 in 1.0 M KOH. The corresponding symmetric two-electrode alkaline water electrolyzer only needs a cell voltage of 1.59 V to afford 10 mA cm^?2 water-splitting current density.     

Direct hydrodeoxygenation of cellulose and xylan to lower alkanes on ruthenium catalysts in subcritical water

Nano particles of Ru, Rh, Pd, Ir, Pt, and Au, protected by polyvinyl pyrrolidone (PVP), were applied to the hydrodeoxygenation of cellulose and xylan in water and 5 MPa H₂ at 543 K. The distributions of products generated from cellulose and xylan were roughly similar to each other under the present reaction conditions, and therefore, the former was intensively studied. The Ru-PVP catalyst afforded mainly methane and lower alkanes, rather than producing water soluble organic compounds, such as diols and alcohols, that were formed with the use of the other catalysts. The changes in the product distributions with reaction temperature and time indicated that the reaction consisted of two consecutive reactions: cellulose or xylan → water soluble compounds → hydrogenolysis. The first transformation was promoted in subcritical water, and the second step was catalyzed by the Ru catalyst. The Ru catalyst that was supported on CeO₂, γ-Al₂O₃, or activated carbon yielded a similar product distribution to that on Ru-PVP; however, the loading of Ru on TiO₂, ZrO₂, SiO₂–Al₂O₃, or SiO₂ resulted in the increment of diols. After the reaction a small portion of the CeO₂ and most of the SiO₂–Al₂O₃ and SiO₂ were dissolved in water, and a portion of the Al₂O₃ was transformed to boehmite AlO(OH) from the γ-alumina. Little change in the catalytic activity however was observed upon the reuse of Ru/Al₂O₃ in the second run.     

Hydrogen production via highly efficient electrocatalyst based on 3D NixCo1-x(OH)2/NiFe-AM induce overall water splitting

The main factors limiting water splitting producing hydrogen production are overpotential, activity and persistence of electrocatalysts. Herein, a novel Ni_xCo_1-x(OH)₂ coupled with NiFe amorphous compound array growing on nickel foam substrate (expressed as Ni_xCo_1-x(OH)₂/NiFe-AM) was developed by facile hydrothermal and electrodeposition methods. Significantly, Ni_xCo_1-x(OH)₂/NiFe-AM with this unique structural exhibits superior activity and stability in the two half reactions of water electrolysis. In addition, when tested in an alkaline electrolyte with a current density of 10 mA cm⁻², the overpotentials of HER and OER was 157 mV and 196 mV (60 mA cm⁻²), respectively. The stability can up to 60 h. These test results show through constructing hierarchical nano-thron architecture enhanced electrocatalytic activity to produce hydrogen and oxygen.