Pd Membrane Research Articles

Combined Hydrogen Potentiometry and Electrochemical Impedance Spectroscopy Approach for Quantification of Oxygen Reduction Kinetics at Buried Metal/Organic Coating Interfaces

Oxygen reduction reaction (ORR) is considered a key electrochemical reaction, the kinetics of which are complex and challenging to quantify, even more at such buried metal/polymer interface. Here in this work, a novel approach independent of the polymer barrier property has been developed to quantitively characterize ORR kinetics using a combined hydrogen potentiometry (HP) and electrochemical impedance spectroscopy (EIS) approach. For the ORR measured using EIS on the front side of a bare Pd membrane exposed to an alkaline NaOH electrolyte, a 5-fold decrease in the charge transfer resistance (RCT) indicated the progress of ORR, in stark contrast to a corresponding 2-fold increase in inert N2 atmosphere. For a polymethyl methacrylate (PMMA)/Pd interface, a 30-fold decrease in RCT as compared to bare Pd correlated well with a cathodic shift of around 50 mV (1 pH unit) in the current-potential I(U) curve. At a molecularly tailored octane-thiol/Pd interface, ORR kinetics was highly inhibited, with the current-potential I(U) curve shifted in the cathodic direction by 190 mV, as compared to the Pd/PMMA interface at a charging (ORR) current of −25 μA cm−2. This could be successfully correlated to a 100-fold decrease in RCT value indicating interface sensitivity of this HP-EIS combined technique.

Preventing H2S poisoning of dense Pd membranes for H2 purification using an electric-field: An Ab initio study

High purity (> 99.9%) H2 is required across a breadth of fields from the energy, chemicals, and semiconductor processing industries and the current multi-step pressure swing adsorption processes are both high cost and inefficient. Dense Pd membranes are highly permeable and selective to H2, but their deployment after steam methane reformation (SMR) is hampered by their vulnerability to poisoning by S species (e.g., H2S). Here, we use Density Functional Theory (DFT) to investigate the use of an applied electric field (AEF) to prevent S poisoning by altering the energetics of H2S adsorption and decomposition on the Pd(111) surface. We find that strong, negative AEFs (<-1.5 V/Å) prevent H2S adsorption without negatively impacting the adsorption or intercalation of H2 into the Pd membrane. Microkinetic simulations of the surface with high strength AEF show long-term (> 80 days) stability even under high 1000 ppm H2S exposure at -1.5 & -2 V/Å E-fields. Although the field strength identified here may be challenging to achieve in operation, these findings suggest that E-fields could provide a pathway for gas phase membrane protection in general and, possibly, more cost-effective H2 purification via stable Pd membrane systems.

Configuration of coupling methanol steam reforming over Cu-based catalyst in a synthetic palladium membrane for one-step high purity hydrogen production

Methanol steam reforming coupled with an efficient hydrogen purification technology to produce high purity hydrogen that feeds for hydrogen fuel cells is an attractive approach to realizing distributed power generation. However, the harmony of catalytic reforming and hydrogen separation with respect to thermodynamics is still an issue. In this work, in order to construct an integrated methanol steam reforming (MSR) reactor for high purity hydrogen production, CuCe/Al2O3 was synthesized by a hydrothermal-impregnated method and a Pd membrane supported by a porous ceramic using the electroless plating method. The results revealed that the catalytic activity and high temperature stability for methanol steam reforming were evidently improved by tuning the copper dispersion, porous structure and the crystal phase. The coupling range with palladium membrane operating temperature was widened. CuCe/Al2O3 presented an excellent stability with a better carbon deposition resistance for the long-term tests than Cu/Al2O3, which exhibited 836.68 μmol/gcat. min of H2 production with low carbon deposition (3.38 wt%) and lower CO emission (0.48 vol%). A 10 μm thick Pd membrane that was deposited on the ceramic support displayed dense and even surface morphology. The effect of palladium membrane structure on hydrogen separation was analyzed. In addition, the influence of temperature on coupling was discussed. Ultimately, high purity of H2 (99.36 vol%) was achieved at 400 °C by integrating the Pd membrane reactor with methanol steam reforming. The internal temperature distribution of the reactor and the effects of feeding conditions were also investigated. This work might offer certain reference for the development of the future distributed integrated hydrogen power generation system, especially in the application of electric vehicles and on-site electricity.

Scale-up analysis of hydrogen rich-stream production from biogas reforming in membrane reactors using numerical modeling

Biogas reforming in membrane reactors has been considered an alternative for hydrogen-rich stream production. Since this technology is not yet applied in industry, the performance of this process can only be evaluated by theoretical simulations. In this work, H2 production employing biogas as feedstock was simulated by Computational Fluid Dynamics in Pd membrane reactors, considering a two-dimensional and non-isothermal model on laboratory and industrial (20 times greater) scales. The most relevant operating parameters were external temperature and residence time (or inlet velocities). An optimal temperature range was proposed (823–948 K) to achieve a balance between reaction performance and H2 permeation rate. Significant thermal gradients were observed on the industrial scale, showing that non-isothermal modeling is crucial for designing a membrane reactor with larger dimensions. The better reaction performance was obtained at lower velocities (<0.046 m s−1), which is also an important information for the optimization and design of the membrane modules.

Bioelectrocatalysis with a palladium membrane reactor

Enzyme catalysis is used to generate approximately 50,000 tons of value-added chemical products per year. Nearly a quarter of this production requires a stoichiometric cofactor such as NAD+/NADH. Given that NADH is expensive, it would be beneficial to regenerate it in a way that does not interfere with the enzymatic reaction. Water electrolysis could provide the proton and electron equivalent necessary to electrocatalytically convert NAD+ to NADH. However, this form of electrocatalytic NADH regeneration is challenged by the formation of inactive NAD2 dimers, the use of high overpotentials or mediators, and the long-term electrochemical instability of the enzyme during electrolysis. Here, we show a means of overcoming these challenges by using a bioelectrocatalytic palladium membrane reactor for electrochemical NADH regeneration from NAD+. This achievement is possible because the membrane reactor regenerates NADH through reaction of hydride with NAD+ in a compartment separated from the electrolysis compartment by a hydrogen-permselective Pd membrane. This separation of the enzymatic and electrolytic processes bypasses radical-induced NAD+ degradation and enables the operator to optimize conditions for the enzymatic reaction independent of the water electrolysis. This architecture, which mechanistic studies reveal utilizes hydride sourced from water, provides an opportunity for enzyme catalysis to be driven by clean electricity where the major waste product is oxygen gas.

Hydrogen Production and Utilization in a Membrane Reactor.

Industrial hydrogenation consumes ~11 Mt of fossil-derived H2 gas yearly. Our group invented a membrane reactor to bypass the need to use H2 gas for hydrogenation chemistry. The membrane reactor sources hydrogen from water and drives reactions using renewable electricity. In this reactor, a thin piece of Pd separates an electrochemical hydrogen production compartment from a chemical hydrogenation compartment. The Pd in the membrane reactor acts as (i) a hydrogen-selective membrane, (ii) a cathode, and (iii) a catalyst for hydrogenation. Herein, we report the use of atmospheric mass spectrometry (atm-MS) and gas chromatography mass spectrometry (GC-MS) to demonstrate that an applied electrochemical bias across a Pd membrane enables efficient hydrogenation without direct H2 input in a membrane reactor. With atm-MS, we measured a hydrogen permeation of 73%, which enabled the hydrogenation of propiophenone to propylbenzene with 100% selectivity, as measured by GC-MS. In contrast to conventional electrochemical hydrogenation, which is limited to low concentrations of starting material dissolved in a protic electrolyte, the physical separation of hydrogen production from utilization in the membrane reactor enables hydrogenation in any solvent or at any concentration. The use of high concentrations and a wide range of solvents is particularly important for reactor scalability and future commercialization.

Hydrogen transport through V–Fe alloy membranes: Permeation, diffusion, effects of deviation from Sieverts’ law

Vanadium alloy membranes are the most promising alternative to commercial membranes of palladium alloy for producing ultrapure hydrogen, while Fe is the most suitable alloying element due to its high ability to reduce the excess hydrogen solubility. Membrane samples from bcc alloys V- κFe (0 ≤ κ ≤ 13.1 at.%) were fabricated in the form of thin-walled tubes with Pd-coated inner and outer sides. The hydrogen permeation and diffusion were studied at inlet pressure of 0.1–0.8 MPa and temperature of 300–450 °C. The hydrogen permeation through the membranes of all the studied alloys turned out significantly higher than through a similar Pd membrane. The hydrogen diffusivity in V- κFe alloys decreased with increasing the alloying degree κ and in any case was somewhat lower than in pure V. The permeation flux continued to increase in proportion to square root of hydrogen pressure even in the region where concentration of dissolved hydrogen approached the solubility limit remaining almost unchanged. This non-Fick behavior was caused by an increase in hydrogen diffusivity, the more significant the greater degree of deviation from Sieverts' law due to approaching the saturation.

Facile self-repair of ultrathin palladium membranes

Pd membranes can play an important role in H2 separation and purification for the development of sustainable and renewable energies. By supporting on porous substrates, Pd layer thickness can be reduced to several micrometers, thus improving the H2 permeance by several orders of magnitude. However, the supported thin Pd membranes are concomitant with pinhole formation due to either fabrication (e.g., electroless-plating) or thermal treatment, which exist as a remarkable challenge for its widespread applications. This study presents a novel and facile approach for self-repair of Pd membrane defects by immersing the stainless-steel supported Pd membranes in PdCl2 solution. Three membranes were deliberately selected with a low selectivity of 152–1687 (400 ​°C, 0.1Mpa), for which disproportionation reactions between Pd2+ and Fe/Cr/Ni at the defect sites spontaneously occur leading to the formation of Pd particles at the exact point of defects. This self-repair process can be enhanced when applying a high pressure of 30–50 ​bar in the PdCl2 solution for 30 ​min, by overcoming the capillary resistance and penetrating through the pinholes. Interestingly, densely distributed hillocks were observed on the membrane surface probably due to reduction of PdCl2 under following H2 treatment, thus increasing the H2 permeance with a higher effective surface area. The H2/N2 selectivity can be improved by more than one order of magnitude (in the best case from 1687 to 8768) and a long-term stability test of 300 ​h was achieved for the repaired membranes, corroborating the application potential of this approach.

Optimal temperature range for the separation of a mixture of 96% protium and 4% deuterium with a palladium membrane

Hydrogen isotope separation can be achieved using a palladium (Pd) membrane because protium (H) and deuterium (D) exhibit different solubility, diffusivity and, hence, mixed-gas permeability in Pd. The permeability of H (kH2) and D (kD2) were evaluated using a 4 vol% D2 – 96 vol% H2 feed mixture at temperatures of 293 K–473 K and pressures of 239 kPa–446 kPa in a continuous Pd membrane separation unit. The Pd foil membrane (0.1 mm thick) is shown to be selective toward H2 over the entire temperature range, with both kH2 and kD2 increasing with temperature. As temperature increases, the mixed-gas selectivity (kH2/kD2) rises from 4.0 at 300 K to a maximum value of 9.6 in the 363 K–373 K temperature range (which represents the operating temperatures that would render the highest concentration of H2 in the permeate and the greatest concentration of D2 in the retentate), then decreases to 6.2 at 480 K. Competitive transport during co-permeation is a likely cause for the maximum separation factor kH2/kD2 observed in this temperature range, being larger than the values predicted using pure gases (2 for diffusion dominant separation). The membrane selectivity presumably decreases from the observed maximum because the reverse solubility isotope effect decreases as the temperature increases. Additionally, isotope diffusion begins to increasingly affect the selectivity at higher temperatures.

Preparation of thin (∼2 μm) Pd membranes on ceramic supports with excellent selectivity and attrition resistance

Thin (∼2 μm) Pd membranes were prepared by two-step electroless plating (ELP) method on porous ceramic supports for hydrogen purification. The two-step ELP method consists of the first ELP, the heat treatment (923 K, N2 and 24 h) and the second ELP. The Pd composite membranes have been characterized by permeation tests with pure gas at 623–873 K and exhibited stable and highest hydrogen permeation flux (∼0.853 mol H2 m−2 s−1) and H2/N2 selectivity (∼88,465) at 823 K under a pressure difference of 0.1 MPa. The Pd composite membranes have been characterized by permeation tests with gas mixtures (H2/N2, H2/CO2) at 623–823 K. The effect of N2 on the hydrogen permeation flux of composite membranes was mainly due to the concentration polarization, and the effect of CO2 was due to concentration polarization at lower temperature (623 K) and a combination of the concentration polarization and chemical reactions at high temperatures (723 and 823 K). The Pd composite membranes have been characterized by attrition resistance tests with particles at 823 K and exhibited high hydrogen permeation stability and H2/N2 selectivity.

Visual hydrogenation of palladium membranes on an elastic substrate and their applications in hydrogen sensing

AbstractThe study of metal‐hydrogen interaction is essential for hydrogen‐related applications. Due to the small permittivity variation of palladium (Pd), it is difficult to visualize its hydrogenation processes. Soft substrates can release the expansion stress of Pd membrane and form wrinkling during hydrogenation, which can be utilized to track the hydrogen diffusion. Here, we investigate the hydrogenation processes of Pd membranes with various shapes and sizes on polydimethylsiloxane (PDMS) substrates. It was found that the Pd membranes priorly wrinkles from the edges during hydrogenation and the saturation time of hydrogen absorption reduces with the decreasing size of Pd membranes. With these measurements, we fabricate a high‐performance optical hydrogen sensor consisted of a Pd nanostripe array on PDMS. Due to the transition from specular reflection to scattering during the surface wrinkling of the Pd nanostripe, when exposed to 4% hydrogen gas mixed with nitrogen gas, the sensor shows a high‐reflectance contrast of more than 800% with the absolute reflectance change exceeding 32% over the visible band, and the response time t90 is about 1.5 seconds. These results suggest that the Pd membranes on an elastic substrate is a promising platform for visualization of hydrogen diffusion and hydrogen detection.

A two-step electroless plating method for Pd composite membranes with enhanced hydrogen selectivity and superior high-temperature stability

Thin Pd membranes were deposited on modified porous YSZ-Al2O3 tubes using a two-step electroless plating (ELP) method for hydrogen separation and purification. The two-step ELP method consists of the first ELP, the heat treatment and the second ELP. The effects of heat treatment conditions in the two-step ELP on the hydrogen selectivity and high-temperature stability of Pd composite membranes were investigated. Pd membranes prepared by different processes exhibit different microstructure and permeation performance. The result shows that Pd membranes prepared by the two-step ELP method and the high-temperature heat treatment (923 K) above the Tamman temperature of pure Pd (> 913 K) between two ELP exhibit the best performance, which is mainly attributed to the two-layer membrane structure and the small Pd crystals in the membranes. The Pd membrane with a thickness of ~6.5 µm prepared via above process exhibited a high and stable hydrogen permeation flux (~0.359 mol H2 m−2 s−1) and a significantly high H2/N2 selectivity (~12,413) for a long-term permeation of 100 h at 873 K under a pressure difference of 0.1 MPa.

The factors affecting the diffusion properties of hydrogen in palladium copper alloys: Ab initio study

The experiments showed that the addition of copper (Cu) in palladium (Pd) membrane reduces the permeability of hydrogen (H) in Pd, and the permeability of H in body-centered cubic (BCC) PdCu alloy is larger than that in face-centered cubic (FCC) PdCu alloy. The underlying reasons are still not well understood. In the present work, systematical ab initio calculations are carried out to investigate the factors affecting the diffusion properties of H in PdCu alloys. It is found that the lowest diffusion barrier of H with zero-point energy correction in BCC PdCu alloy (0.016 eV) is relatively low than that in FCC PdCu alloy (0.346 eV). The interactions among interstitial H atoms are significantly repulsive in BCC PdCu alloy, while it is attractive in FCC PdCu alloy. The results suggest that it is energetically favorable to form interstitial H cluster in FCC PdCu alloy rather than that in BCC PdCu alloy. The formation of interstitial H clusters impedes the fast movement of H in FCC PdCu alloy. The presence of intrinsic vacancy in FCC PdCu alloy further hinders the migration of H. It is found that the binding strength of vacancy with H in FCC PdCu alloy is much larger than that in BCC PdCu. The stronger the combination of H and vacancy, the greater the obstacle to the movement of H in PdCu alloy. All these results elucidate the experimental phenomena why H penetration ability in FCC PdCu alloy is weaker than that in BCC PdCu alloy.

Comparative study on the numerical simulation of hydrogen separation through palladium and palladium–copper membranes

The hydrogen (H2) diffusion through palladium (Pd) and Pd–copper (Cu) membranes was numerically investigated by developing a two-dimensional computational fluid dynamics model for predicting the performance of H2 separation. The momentum and mass transport phenomena in the laminar flow conditions were solved at different operating conditions in a vertical cylindrical-type reactor. The effect of feed-gap distance, H2 concentration, and reactor heating temperature on the H2 permeation processes were simulated and compared for both Pd-based membranes. The concentration, velocity, and convective and diffusion mass transfer flux distributions were analyzed using the designed model. The H2 concentration was proportional to the feed-gap distance/cross-sectional area. The smaller the feed-gap distance, the greater the probability of a H2 molecule being adsorbed by the membrane surface and the ionization energy increasing, leading to further H2 dissociation through the Pd-based membranes. It was found that the diffusion flux of all feed concentrations was substantially decreased 50 s after the start of the permeation process. Moreover, the diffusion flux of the Pd–Cu40% membrane was relatively larger than that of the pure Pd membrane under the same operating conditions. The distributions of the convective flux, diffusion mass transfer flux, and concentration of the Pd–Cu40% membrane were substantially increased up to 350 °C, then fell to a lower value at higher temperatures. The simulation results were validated with the experimental results, with analysis indicating a good agreement with the experimental results under the same operating conditions. It can be concluded that the simulation modeling for Pd-based membranes was able to predict the optimum operating conditions at high H2 diffusion rates.

Hydrophobically modified Pd membrane for the efficient purification of hydrogen in light alcohols steam reforming process

The ability to selectively remove H2 from the product has made palladium (Pd) membrane reactor a good choice for steam reforming reaction. However, carbonaceous deposited on the surface of Pd membrane during reaction hindered its industrial application. In order to protect Pd membrane from being poisoned by water and light alcohols, a TS-1/Pd composite membrane was prepared by a facile one-step hydrothermal method combined with silane coupling treatment. The zeolite layer acted as a protective armor by keeping poisonous species away from the Pd bulk, and the silanization process increased the hydrophobicity by reducing the hydroxyl density on the surface of TS-1/Pd composite membrane. After 100 h’s exposure in the steam reforming condition, the percentage of carbon content was only 0.95% for the TS-1/Pd membrane, compared with 13.20% for the pure Pd membrane. The H2 permeability and H2/N2 selectivity of the TS-1/Pd remained constant, while that for pure Pd membrane fell by 50% and 80%, respectively. The significantly improved resistance to carbon deposition provides possibility for the large-scale application of Pd membrane reactor in hydrogen production via steam reforming.

Fluorine-free synthesis of all-silica STT zeolite membranes for H2/CH4 separation

Hydrogen (H2) is the most promising alternative to fossil energy for zero-emission of CO2. However, the by-produced H2 from coking process was generally burned as fuel. It is highly desired to recycle the H2 from coke oven gas as the clean energy resource. Herein all-silica STT zeolite membranes were prepared from the fluorine-free precursor for H2/CH4 separation. The crystallization period was shortened by 75% at the elevated temperature. After hydrothermal synthesis of 2 days, the membrane showed H2 permeance up to 2.8 × 10−8 mol·m−2·s−1·Pa−1 and H2/CH4 selectivity up to 49.6 at 0.2 MPa and 298 K. More importantly, STT zeolite membrane was resistant to CO and H2S, which should be prevented from feeding to the commercial polymeric and Pd membranes. The membrane was stable up to 336 h in the simulated coke oven gas of 63 H2: 28 CH4: 7 CO: 2 C2H6 containing 100 ppm H2S. This would pave the way of zeolite membranes to H2 separation in practical applications.

Vacuum-assisted continuous flow electroless plating approach for high performance Pd membrane deposition on ceramic hollow fiber lumen

Pd-based membranes have wide applications in H2-related fields given their excellent selectivity in H2 separation. Despite their unique advantages, the fabrication of continuous and dense Pd membrane layer in the lumen side of the hollow fibers remains a great challenge. Herein, a vacuum-assisted continuous flow electroless plating (VCFELP) approach was developed to deposit a 4 μm-thick compact Pd membrane layer on the lumen (i.e., inner surface) of YSZ-Al2O3 composite hollow fiber with outer and inner diameter of 1.5 and 1.0 mm, respectively. The Pd membrane displayed hydrogen flux of ∼0.075 mol m−2 s−1 at 773 K and the nitrogen was undetectable through bubble flow meter and gas chromatograph. Furthermore, the stability and durability of the Pd membrane were significantly improved by the VCFELP approach with the aid of vacuum and continuous flow system. The outstanding membrane stability was verified by the 240-h long-term operation, with up to 24 cycles of H2–N2 gas exchange tests, 40 thermal cycle tests (from high to low temperature) and 20 pressure cycle tests. Furthermore, the Pd membrane showed sufficient stability and excellent reaction performance during the 120-h reaction run in the one-step oxidation of benzene to phenol using hydrogen and oxygen as co-reactants, achieving the benzene conversion and phenol selectivity of 23.5% and 91.6%, respectively.

On the long-term stability of Pd-membranes with TiO2 intermediate layers for H2 purification

This work addresses the use of TiO 2 -based particles as an intermediate layer for reaching fully dense Pd-membranes by Electroless Pore-Plating for long-time hydrogen separation. Two different intermediate layers formed by raw and Pd-doped TiO 2 particles were considered. The estimated Pd-thickness of the composite membrane was reduced in half when the ceramic particles were doped with Pd nuclei before their incorporation onto the porous support by vacuum-assisted dip-coating. The real thickness of the top Pd-film was even lower (around 3 μm), as evidenced by the cross-section SEM images. However, a certain amount of palladium penetrates in some points of the porous structure of the support up to 50 μm in depth. In this manner, despite saving a noticeable amount of palladium during the membrane fabrication, lower H 2 -permeance was found while permeating pure hydrogen from the inner to the outer surface of the membrane at 400 °C (3.55·10 −4 against 4.59·10 −4 mol m −2 s −1 Pa −0.5 ). Certain concentration-polarization was found in the case of feeding binary H 2 –N 2 mixtures for all the conditions, especially in the case of reaching the porous support before the Pd-film during the permeation process. Similarly, the effect of using sweep gas is more significant when applied on the side where the Pd-film is placed. Besides, both membranes showed good mechanical stability for around 200 h, obtaining a complete H 2 /N 2 ideal separation factor for the entire set of experiments. At this point, this value decreased up to around 400 for the membrane prepared with raw TiO 2 particles as intermediate layer (TiO 2 /Pd). At the same time, complete selectivity was maintained up to 1000 h in case of using doped TiO 2 particles (Pd–TiO 2 /Pd). However, a specific decrease in the H 2 -permeate flux was found while operating at 450 °C due to a possible alloy between palladium and titanium that is not formed at a lower temperature (400 °C). Therefore, Pd–TiO 2 /Pd membranes prepared by Electroless Pore-Plating could be very attractive to be used under stable operation in either independent separators or membrane reactors in which moderate temperatures are required. • Pd-doped titania highly reduces the Pd-thickness for reaching fully dense membranes. • TiO 2 barriers yield H 2 permeance up to 4.17·10 −4 mol/s m 2 Pa 0.5 and complete α H2/N2 . • Pd-doped titania allows stability for long-time operation up to 1000 h at 400 °C. • Temperature above 450 °C leads to certain PdTi alloy and H 2 permeance decrease.

C≡N triple bond cleavage via transmembrane hydrogenation

Renewable-energy-powered electrosynthesis is an emerging green alternative to thermochemical routes. Against this backdrop, acetonitrile valorization is an important target because it is industrially produced in excess. Here we developed a catalytic system that converts acetonitrile into acetaldehyde and NH3 using an H-permeable Pd membrane reactor. In this system, H is abstracted from water in an aqueous electrolyte and transferred across the Pd membrane and is used to hydrogenate acetonitrile with up to 60% faradic efficiency (FE) for NH3 generation. We also constructed a unique infrared (IR) spectroelectrochemical cell that enabled us to probe the reaction as it occurred. This helped us deduce that the reaction proceeded through an imine hydrolysis pathway. Finally, we extended the scope of this system to four additional nitrile reactants. This work establishes a new electrochemical route to nitrile hydrogenation and opens up promising avenues in electrosynthetic technologies.

Design and multiobjective optimization of membrane steam methane reformer: A computational fluid dynamic analysis

A membrane reactor affords promising advantages for processes; however, it faces many issues such as the high cost, manufacturing complexity, and ineffective zones. In this numerical analysis, we propose a design and multiobjective optimization of membrane steam methane reforming reactor to attain an effective arrangement for high hydrogen yield and separation. Four configurations were investigated for comparative analysis, adopting continuous and segmented catalyst and membrane arrangements; thereafter, the genetic algorithm optimization approach was applied. The advantages of the proposed membrane and catalyst design were shown and justified. Compared to the conventional case, the results showed high hydrogen yield and separation in the design case, despite the significant reduction in the Pd membrane length. For the optimal case, further improvement of the hydrogen separation and high hydrogen yield were achieved with 20% less catalyst load and an 80% reduction in the membrane length as the membrane was effectively embedded, which can significantly reduce the cost of the process. Furthermore, the complexity of the membrane reactor was avoided as the reaction and the separation were conducted separately.