Low Hydrogen Research Articles

Reduced graphene oxide assembled on the Si nanowire anode enabling low passivation and hydrogen evolution for long-life aqueous Si-air batteries

Silicon-air batteries (SABs), a new type of semiconductor air battery, have a high energy density. However, some side reactions in SABs cause Si anodes to be covered by a passivation layer to prevent continuous discharge, and the anode utilization rate is low. In this work, reduced graphene oxide (RGO) fabricated via high-temperature annealing or L-ascorbic acid (L.AA) reduction was first used to obtain Si nanowires/RGO-1000 (Si NWs/RGO-1000) and Si nanowires/RGO-L.AA (Si NWs/RGO-L.AA) composite anodes for SABs. It was found that RGO suppressed the passivation and self-corrosion reactions and that SABs using Si NWs/RGO-L.AA as the anode can discharge for more than 700 hours, breaking the previous performance of SABs, and that the specific capacity was increased by 90.8% compared to bare Si. This work provides a new solution for the design of high specific capacity SABs with nanostructures and anode protective layers.

Insights into support effects of Ag/SiO2 catalysts for dimethyl glycolate semi-hydrogenation to methyl glycolate

Support materials play vital roles in heterogenous catalysis via the so-called support effects, and understanding on the support effects is beneficial for the design of high-performance catalysts. Herein, we represent detailed investigations on the support effects of Ag catalysts for dimethyl glycolate (DMO) semi-hydrogenation to methyl glycolate (MG), where G6 silica with amorphous mesopores, SBA-15 with parallel mesopores and silica nanospheres (MSNS) with center-radial ones were employed as the supports. The hydrogenation activity decreases in the order of Ag/MSNS > Ag/SBA-15 > Ag/G6 while the MG selectivity in the order of Ag/G6 > Ag/MSNS > Ag/SBA-15 at the same reaction conditions, indicating remarkable support effects on both activity and selectivity. Structural characterizations, temperature programmed experiments and in-situ FTIR of DMO adsorption experiments demonstrate that the weak confinement effect of G6 leads to the larger sized Ag nanoparticles and weakened activation of DMO and H2, which contributes to low hydrogenation activity. In contrast, the ordered mesoporous SBA-15 and MSNS deliver well confinement effects for Ag nanoparticles and the activation of DMO and H2, but the distinct pore structures result in different activation and diffusion behaviors. Finally, DMO conversion and MG yield are well correlated with the competitive adsorption of H2 versus DMO on Ag catalysts, indicating such competitivity as a descriptor for DMO semi-hydrogenation over Ag catalysts.

A numerical study on hydrogen blending in natural gas pipeline by a T-Pipe

In order to study the flow blending and transporting process of hydrogen that injects into the natural gas pipelines, a three-dimensional T-pipe blending model is established and the flow characteristics are investigated systematically by the large eddy simulation (LES). Firstly, the mathematical formulation of hydrogen-methane blending process is provided and the LES method is introduced and validated by a benchmark gas blending model having experimental data. Subsequently, the T-pipe blending model is presented, and the effects of key parameters, such as the velocity of main pipe, hydrogen blending ratio, diameter of hydrogen injection pipeline, diameter of main pipe and operating pressure on the hydrogen-methane blending process, are studied systematically. The results show that, under certain conditions, the gas mixture will be stratified downstream of the blending point, with hydrogen at the top of the pipeline and methane at the bottom of the pipeline. In the no-stratified scenario, the mixing distance increases at lower hydrogen mixing ratio and larger diameter of the hydrogen injection pipe or the main pipe. Finally, based on the numerical results, the underlying physics of the stratification phenomenon during the blending process are explored and an indicator for stratification is proposed using the ratio between the Reynolds numbers of the natural gas and hydrogen.

Day-ahead dispatch of electricity-hydrogen systems under solid-state transportation mode of hydrogen energy via FV-IGDT approach

Hydrogen energy has the advantages of being clean and carbon-free, convenient storage, and easy conversion to electrical energy. The use of renewable energy electrolysis for hydrogen production is an important solution to promote clean energy utilization and decarburization in the power and transportation industries. However, hydrogen has a low hydrogen storage density and is prone to explosion. The high cost and risk of hydrogen transportation pose challenges to the promotion and utilization of hydrogen. To address these difficulties, this paper proposes a day-ahead dispatch of electricity-hydrogen systems (EHS) under the solid-state transportation mode of hydrogen energy. Firstly, based on the Van't Hoff equation, the relationship between gas pressure and the reaction temperature is established during the gas-solid conversion process, and a hydrogen energy solid-state transport model based on a magnesium-based hydrogen transport vehicle (MHTV) is proposed. Secondly, a renewable energy uncertainty set is established based on the information-gap decision theory (IGDT) envelope constraint for addressing the uncertainty of renewable energy and a day-ahead bi-level dispatch model of the EHS is constructed based on the solid-state transportation mode of hydrogen energy. Finally, the IGDT approach considering fuzzy variables (FV-IGDT) is presented by using a fuzzy variable membership function, and the proposed bi-level model is transformed into a single-level model for a solution based on this approach. The effectiveness of the proposed model and solution method is verified through simulation on an EHS consisting of a modified IEEE-118 power system, 2 hydrogen production stations (HPS), and 10 hydrogen refueling stations (HRS).

Using electrolytic hydrogen production and energy storage for balancing a low carbon electricity grid: Scenario assessments for India

Nuclear reactors and variable renewables will play a significant role in the global energy transition as providers of low carbon electricity to various end use sectors. Real time balancing of power demand and supply without modulation or curtailment is possible using electrolytic hydrogen plants and energy storage systems. The generation mix adopted and load profiles are unique to a country and this study considers the specific case of India. This work analyses the use of grid connected water electrolysers, grid scale battery storage, hydrogen storage and fuel cells as flexible loads and dispatch schemes for grid balancing. Based on postulated long term power generation scenarios for India, the minimum required system sizes for grid balancing are estimated and techno-economic uncertainties are assessed. The use of water electrolysers is prioritized to make use of excess power, while minimizing battery storage requirement. This scheme can potentially produce a substantial share of low carbon hydrogen in India for use in industrial decarbonization, thus reducing the need for additional generation infrastructure.

Impact of gas type on microfluidic drainage experiments and pore network modeling relevant for underground hydrogen storage

Underground hydrogen storage (UHS) in geological reservoirs is proposed as a technically feasible solution to balance mismatch between supply and demand in emerging markets. However, unique hydrogen properties and coupled flow mechanisms require new investigations to fully understand transport and storage of hydrogen in porous media across scales. Here we use microfluidics to investigate the effect of gas type and injection rate on flow patterns, saturation and connectivity of the gas phase. We visually observe that gas flow is characterized by capillary fingering, further confirmed by fractal dimension analysis. At lower injection rates, the gas saturation after drainage appears to increase with gas viscosity, with lower hydrogen saturation compared to methane and nitrogen. The maximum gas saturations (39–46 %) were achieved at higher injection rates, showing no clear correlation to gas type. However, the high-rate injections lead to undesired outcomes in terms of formation of disconnected gas ganglia, mostly pronounced for nitrogen. We identify an optimal injection rate to achieve maximum gas saturation with the least amount of disconnected gas. The experimental results are supported with pore network modeling to derive relative permeability and capillary pressure functions.

Sensitivity study of integrated carbon capture and methanation process using dual function materials

Integrated Carbon Capture and Methanation (ICCM) is a promising technology to produce Synthetic Natural Gas (SNG) via captured CO2 and renewable hydrogen. This work performed a sensitivity study on how operation pressure, the types of DFM and point source, and the catalytic metal loading in DFMs affect the performance of ICCM process. As Na-Ru/Al2O3 (Na-DFM), (Li-Na-K)NO3-MgO-Ni/CeO2-phy (Mg-DFM), and Ni5-CeLi (Li-DFM) were adopted as DFMs, the performances of ICCM process were investigated in the range of 0.1 Mpa-5.0 Mpa, showing elevated pressure is favorable to improving capture efficiency and the quality of SNG products, and reducing hydrogen consumption. Under the optimized operation conditions, Na-DFM based ICCM system shows the better overall performance than ICCM system using Mg-DFM or Li-DFM, which energy conversion efficiency, comprehensive energy consumption, and net CO2 emission are 82.74 %, –14.61 MJ/kg CO2, and –1.18 kg CO2/kg CO2, respectively. Circulation rate is the amount of DFMs necessary to be transferred between reactors to ensure the desired CO2 capture efficiency or SNG productivity; it heavily depends on the type of adsorbent component, capture/hydronation reactions, and the fraction of active adsorbent component in DFMs for CO2 transport. Na-DFM based ICCM systems using different point sources (Power Plant, Steel Plan, and Cement Plant) possess the approximate performances in terms of energy conversion efficiency, comprehensive energy consumption, net CO2 emission, and SNG composition; but when Steel Plan is the point source, Na-DFM based ICCM process features of low electricity and hydrogen consumptions. Cyclic redox reactions of catalytic metal and the cycled capture/hydrogenation proceed in parallel in ICCM process. The increased hydrogen consumption and strong exothermic effects arising from the redox reactions of catalytic metal leads to profound performance changes of ICCM system. Overall, the present work is providing comprehensive information and necessary data to guide the design and operation of an ICCM plant.

Additively Manufactured Silicone Polymer Composite with High Hydrogen Getter Content and Hydrogen Absorption Capacity.

Hydrogen getters consisting of 1,4-bis[phenylethynyl] benzene (DEB) and a carbon-supported palladium catalyst (Pd/C) have been used to mitigate the accumulation of unwanted hydrogen gas in a sealed system. Here, we report the formulation of a composite resin consisting of silicone polymer plus DEB-Pd/C as an active getter material and the additive manufacturing of silicone getter composites with a high getter content (up to 50 wt %). NMR and DSC studies suggest no reaction between the silicone polymer resin and DEB even at elevated curing temperatures (75 °C). Getter composites with varying amounts of getter and filler were formulated, and their rheological properties were studied. The two composite resins with good printability parameters and different getter contents were chosen to make 3D-printed samples. The hydrogen absorption capacity of these samples was studied at a low hydrogen pressure of 750 mTorr of pure hydrogen. The getter composite with 50 wt% of getter showed normalized DEB conversion of 83%, with the hydrogen adsorption capacity of 100.2 mL of H2 per gram of polymer getter composite.

Hydrogen adsorption and diffusion behavior in kaolinite slit for underground hydrogen storage: A hybrid GCMC-MD simulation study

Underground hydrogen storage (UHS) in reservoirs offers the opportunity for large-scale and long-term storage of hydrogen. In order to understand the fundamental mechanisms of hydrogen storage and transportation, it is crucial to study the adsorption and diffusion behavior of hydrogen in reservoirs. By utilizing a hybrid GCMC and MD simulation procedure, we investigated the adsorption and diffusion behavior of hydrogen in kaolinite slit with pore sizes ranging from 1 to 20 nm at pressures up to 30 MPa and temperatures ranging from 303 to 423 K. Hydrogen distribution, excess adsorption, diffusion coefficient, and gas–solid interaction energy were analyzed in relation to pore size, temperature, pressure, and mineralogy. When pores are larger than 5 nm, most of the hydrogen is located in the bulk phase, resulting in insignificant hydrogen loss due to adsorption. Therefore, reservoirs with pores larger than 5 nm are suitable for UHS. Reservoirs with low temperatures and high hydrogen pressures are conducive to UHS, but the hydrogen mobility is reduced. The mineralogy of the formation results in pore surfaces with different charge properties, which significantly affects hydrogen storage. Although van der Waals interaction dominates the gas–solid interaction, Coulomb interaction remains important. The negatively charged pore surface mitigates the gas–solid Coulomb interaction, thereby preventing hydrogen loss through adsorption. This study enhances our understanding of hydrogen storage mechanisms in subsurface porous media and elucidates the influence of various factors. Consequently, it provides a theoretical framework for selecting UHS sites.

Nanoporous Nickel Cathode with an Electrostatic Chlorine-Resistant Surface for Industrial Seawater Electrolysis Hydrogen Production.

Seawater electrolysis presents a promising avenue for green hydrogen production toward a carbon-free society. However, the electrode materials face significant challenges including severe chlorine-induced corrosion and high reaction overpotential, resulting in low energy conversion efficiency and low current density operation. Herein, we put forward a nanoporous nickel (npNi) cathode with high chlorine corrosion resistance for energy-efficient seawater electrolysis at industrial current densities (0.4-1 A cm-2). With the merits of an electrostatic chlorine-resistant surface, modulated Ni active sites, and a robust three-dimensional open structure, the npNi electrode showed a low hydrogen evolution reaction overpotential of 310 mV and a high electricity-hydrogen conversion efficiency of 59.7% at 400 mA cm-2 in real seawater and outperformed most Ni-based seawater electrolysis cathodes in recent publications and the commercial Ni foam electrode (459 mV, 46.4%) under the same test condition. In situ electrochemical impedance spectroscopy, high-frame-rate optical microscopy, and first-principles calculation revealed that the improved corrosion resistance, enhanced intrinsic activity, and mass transfer were responsible for the lowered electrocatalytic overpotential and enhanced energy efficiency.

Low detection based on Pd Pt /In2O3 nanospheres for rapid hydrogen detection

Semiconductor gas sensors still have limitations in realizing rapid hydrogen measurement in lower hydrogen concentration environments. Therefore, in this paper, In2O3 cloud-like spherical hydrogen detection sensing materials with different Pd and Pt ratio loading were successfully prepared using the water bath method. The In2O3 sensing materials modified with noble metals Pd and Pt were designed for the rapid detection of hydrogen at 400 ppb with good selectivity under mixed gas components. The crystalline phase, morphology, and chemical composition of the prepared Pd and Pt-loaded In2O3 samples were analyzed using characterization techniques. The gas-sensing results showed that the In2O3 gas-sensing sensor with a Pd and Pt ratio loading of 1–2 had stronger H2 sensing performance at the optimum operating temperature (350°C). The response time and recovery time of In2O3 loaded with the opinion ratio at 350℃ and 400 ppb were 1 s and 15 s. The low detection limit was 400 ppb, with good repeatability and long-term stability. Finally, the enhanced gas sensitization mechanism of the In2O3 gas sensor loaded with Pd and Pt for H2 was discussed.

Hydrogen reduction-based energy management strategy of hybrid fuel cell/PV/battery/supercapacitor renewable energy system

Fuel cells can be used in sustainable cities for a variety of purposes, including emergency backup power systems, electric vehicle recharging, and the production of clean, efficient energy for buildings. Additionally, fuel cells can support distributed energy systems, improving energy management, and lowering dependency on conventional energy sources. However, the slow time response of proton exchange membrane fuel cell (PEMFC) during high-level load variation is an issue that needs addressing. To solve this, battery storage and supercapacitor can be integrated with a hybrid generation system including fuel cell, photovoltaic (PV). It's important to have effective energy management strategies (EMSs) to ensure the photovoltaic (PV) array, PEMFC, batteries, and supercapacitors function optimally. An EMS distributes the load demand among these components while maintaining high efficiency and low hydrogen consumption. This paper proposes an effective EMS for a hybrid generating system DC microgrid (MG) having PV, FC, battery, and SC based on recent Harris hawks optimizer (HHO) to manage the energy between the equipment while minimizing the total hydrogen consumption and enhancing the system efficiency. The research work compared several algorithms, including external energy maximization strategy (EEMS), equivalent consumption minimization strategy (ECMS), frequency decoupling and state machine control (FDSMC), proportional integral (PI), Cuckoo search (CS), and grey wolf optimizer (GWO), with the proposed HHO. The EEMS-based HHO algorithm outperformed the others resulting in 18.95 %, 38.77 %, 47.34 %, 34.43 %, 33.9 %, and 20.38 % hydrogen consumption reduction compared to PI, FDSMC, ECMS, EEMS, CS, and GWO, respectively. Moreover, efficiency improved by 7.62 %, 7.77 %, 17.15 %, 11.21 %, 2.17 %, and 5.12 % compared to PI, FDSMC, ECMS, EEMS, CS, and GWO, respectively. The obtained findings demonstrated the robustness and efficacy of the suggested HHO-EMS in obtaining the lowest hydrogen consumption of the DC microgrid that was provided.

Subsidizing Grid-Based Electrolytic Hydrogen Will Increase Greenhouse Gas Emissions in Coal Dominated Power Systems.

Clean hydrogen has the potential to serve as an energy carrier and feedstock in decarbonizing energy systems, especially in "hard-to-abate" sectors. Although many countries have implemented policies to promote electrolytic hydrogen development, the impact of these measures on costs of production and greenhouse gas emissions remains unclear. Our study conducts an integrated analysis of provincial levelized costs and life cycle greenhouse gas emissions for all hydrogen production types in China. We find that subsidies are critical to accelerate low carbon electrolytic hydrogen development. Subsidies on renewable-based hydrogen provide cost-effective carbon dioxide equivalent (CO2e) emission reductions. However, subsidies on grid-based hydrogen increase CO2e emissions even compared with coal-based hydrogen because grid electricity in China still relies heavily on coal power and likely will beyond 2030. In fact, CO2e emissions from grid-based hydrogen may increase further if China continues to approve new coal power plants. The levelized costs of renewable energy-based electrolytic hydrogen vary among provinces. Transporting renewable-based hydrogen through pipelines from low- to high-cost production regions reduces the national average levelized cost of renewables-based hydrogen but may increase the risk of hydrogen leakage and the resulting indirect warming effects. Our findings emphasize that policy and economic support for nonfossil electrolytic hydrogen is critical to avoid an increase in CO2e emissions as hydrogen use rises during a clean energy transition.

Highly efficient and direct recovery of low-pressure hydrogen isotopes from tritium extraction gas by PdY alloy membrane permeator

Low-pressure hydrogen recovery is crucial for the fusion reactor deuterium-tritium fuel cycle, and the usual treatment is achieved through multiple steps of enrichment and separation, which has the drawbacks of complex processes and high energy consumption. In this work, a membrane permeator including 12 sets of Pd92Y8 at% alloy tubes has been investigated for the permeability and extraction of hydrogen in low-pressure mixtures. The hydrogen permeation through dense Pd-based membrane mechanism and corresponding Sieverts’ exponents have been verified. The concentration polarization effect is deducted from the results. Through pure hydrogen permeation test, the cold-rolling 80 μm thick Pd92Y8 at% membrane has hydrogen permeability at 400 °C of 3.43×10−8 mol∙m−1∙s−1∙Pa−0.5, which is higher than that of PdAg alloy membrane under the same conditions. Highly efficient recovery efficiency has been achieved for low hydrogen pressure mixtures, and the PdY alloy membrane permeator with 678 cm2 effective area could reach around 95% hydrogen extraction recovery for 0.1 mol% hydrogen-helium mixture and 97.74% recovery for 0.33 mol% at the rate of 21 standard liter per minute (SLM). It indicates that the PdY alloy membrane permeation can be an alternative solution for efficiently recovering low-pressure hydrogen isotopes in tritium extraction gas.

Effects of riboflavin application on rice growth under salinized soil conditions

Salt-sensitive crop varieties suffer from oxidative stress as a consequence of osmotic and ionic stresses in plants under salinity stress. This study is aimed at identifying the effects of riboflavin (RIB) application on uplifting rice growth under salinized soil condition. Two-week-old seedlings of IR29 (a salt-sensitive variety) were supplemented with 0.5 μM of RIB, and 50 mM of NaCl was supplied for 2 weeks, inducing salinized soil conditions. The results indicated that RIB pretreatment (RP) seedlings possessed higher plant biomass, and lower electrolyte leakage ration (ELR), hydrogen peroxide (H2O2) and malondialdehyde (MDA) concentrations, higher chlorophyll, magnesium (Mg), and iron (Fe) concentrations in the leaf blades, a higher proline concentration, and a lower Na+ concentration in the leaf blades. To further understand the mechanisms behind the difference in plant growth between the RP and non-RP seedlings, molecular analysis revealed that RP seedlings upregulated OsNHX1 and OsHKT1;5 expressions were observed in the roots of RP seedlings, regulating Na+ uptake through the transpiration stream and reducing Na+ concentration in the leaf blades. Collectively, these results suggest that RP is a potent method for improving plant growth under salinized soil conditions.

Waste-derived catalysts for tar cracking in hot syngas cleaning

Catalytic tar cracking is a promising technique for hot syngas cleaning unit in gasification plants because it can preserve tars chemical energy, so increasing the syngas heating value. The cost associated with catalyst preparation is a key issue, together with its deactivation induced by coke deposition. Iron is a cheap and frequently used catalyst, which can also be found in some industrial wastes. The study aims to assess the catalytic efficiency for tar cracking of two waste-derived materials (red mud and sewage sludge) having high content of iron. The catalysts were supported on spheres of γ-Al2O3, and their efficiency was compared to that of a pure iron catalyst. The role of support was investigated by testing pure red mud, with and without the support. A series of long-term tests using naphthalene as tar model compound were carried out under different values of process temperatures (750 °C-800 °C) and steam concentrations (0 %-7.5 %). The waste derived catalysts showed lower hydrogen yields compared to pure iron catalyst, due to their lower content of iron. On the other hand, the conversion efficiencies of all the tested catalysts resulted rather similar, since the Alkali and Alkaline-Earth Metallic species present on the surface of waste-derived catalyst help in preventing coke deposition. The iron oxidation state appears to play an important role, with reduced iron more active than its oxidised form in the tar cracking reactions. This indicates the importance of tuning steam concentration to keep constant the reduced state of iron while limiting coke deposition.

Hydrogen diffusion and hydrogen embrittlement of a 1500 MPa hot-stamped steel 22MnB5 in different austenitizing conditions

We investigated the influence of hydrogen on a 1500 MPa hot-stamped steel 22MnB5 with different prior austenite grain size (PAGS, ranging from 14.0 μm to 22.2 μm), which were produced by precise control of the austenitizing temperature and time. All steel specimen exhibited a significant reduction of ductility (e.g., by 70%) and a small decrease in ultimate tensile strength (≤15%), measured using the linearly increasing stress test. The effect of PAGS on hydrogen embrittlement of the hot-stamped steel was not significant for these test conditions. Martensite with smaller PAGS exhibited a slightly lower hydrogen diffusion coefficient. Fracture for all steel variants after yielding occurred for hydrogen contents greater than those that actually occur during service.

Policy Implementation Roadmap, Diverse Perspectives, Challenges, Solutions Towards Low-Carbon Hydrogen Economy

Hydrogen is a nearly emission-free energy carrier with many enticing qualities, including wide availability, environmental friendliness, and a high calorific value. There have constantly been a lot of challenges to establish an entire fledge low carbon hydrogen economy in the past century. This study aims to critically analyse the economic, environmental, technological, and policy implementation and division of low-carbon hydrogen to find novel solutions, bridging the gaps and giving a perspective approach to the study. Differentiation of various low carbon hydrogen (LCH) components, including green and blue hydrogen, was also proposed based on the life cycle assessment emissions (LCAE). Current policy perspectives and Promised Pledged Perspectives are considered to project hydrogen demand in 2030. A thorough economic analysis of low-carbon hydrogen system technologies is also conducted from both hydrogen production and storage perspectives by comparing various production and storage systems. Current Policies towards LCH were critically viewed from policymakers, consumers, and R & D perspectives, through which several challenges, gaps, and keynote necessities were also stated.

In-situ growth 2D Fe2P nanosheets on the surface of 1D Cd0.9Zn0.1S nanorods for remarkably improved photocatalytic H2 evolution

Loading cocatalysts can effectively reduce the hydrogen production overpotential and provide additional catalytic sites. Fe2P, with abundant active sites, low hydrogen evolution overpotential, is regarded as a promising cocatalyst to replace the noble metals. Fe2P nanosheets were grown in situ on the surface of Cd0.9Zn0.1S nanorods to form unique 2D/1D structure, which was designed to enlarge the interface contact between them. The maximum hydrogen evolution rate was as high as 38.48 mmol h−1 g−1, which was even higher than that of noble metal Pt modified Cd0.9Zn0.1S. The results of characterization and theoretical computation demonstrated that the electronic interaction existed between Fe2P and Cd0.9Zn0.1S, and Fe2P as cocatalyst collected electrons to facilitate the transfer and separation of electrons and holes. This work investigated the transfer process of photogenerated carriers and revealed the photocatalytic mechanism through a combination of theoretical calculation and experimental characterization.

Removal of molybdenum by TBP-TRPO extraction in sodium isopolytungstate solution

A new process was proposed for extracting molybdenum from tungsten solutions in acidic tungsten-molybdenum mixed solution. The extraction ratio of molybdenum reached 70 % and the tungsten-molybdenum separation factors reached 400 with the hydrogen peroxide dosage of nH2O2/n(Mo) = 2 (nH2O2/n(W + Mo) = 0.3) for the molybdenum-containing isopolytungstate sodium solution. The experimental conditions resulted in the yield of only 20 % of the traditional method (nH2O2/n(W + Mo) = 1.5–2). The organic phases consisted of 2 % TRPO and 60 % TBP. The saturated extraction capacity of molybdenum was found to be 10 g/L. The solution of 0.3 mol/L sodium bicarbonate was used as the stripping agent. With the temperature of 25 ℃, stripping time of 6 min, and the phase ratio of (O/A)2, the stripping ratio of molybdenum was 90 % and that of tungsten was 70 %. The extraction mechanism of TBP-TRPO and the hydrogen peroxide coordination were analyzed using Raman and infrared analyses. The process has a high industrial potential due to its low hydrogen peroxide dosage, high molybdenum extraction ratio, high separation factor, and low cost.