Influence of basic dopants on the activity of Ru/Pr6O11 for hydrogen production by ammonia decomposition

Basic oxides such as alkali metal oxides, alkaline earth metal oxides, and rare earth oxides were added to Ru/Pr₆O₁₁, and the activity of the catalysts with respect to hydrogen production by ammonia decomposition was investigated. Ru/Pr₆O₁₁ doped with alkali metal oxides, except for Li₂O, achieved higher NH₃ conversions than bare Ru/Pr₆O₁₁. Cs₂O, the most basic of the alkali metal oxides, was the most effective dopant. In contrast, other dopants with lower basicity than the alkali metal oxides achieved lower NH₃ conversions than bare Ru/Pr₆O₁₁. Changing the Cs/Ru molar ratio revealed that the best Cs/Ru ratio was 0.5–2; the reaction was effectively promoted without negative effects from coverage of the Ru surface by the Cs₂O. Varying the order of loading the Ru and Cs₂O onto Pr₆O₁₁ revealed that loading Ru onto Cs₂O/Pr₆O₁₁ was an effective way to enhance NH₃ conversion, and coverage of the Ru surface was reduced.     

3D simulation of hydrogen production by ammonia decomposition in a catalytic membrane reactor

Ammonia decomposition in an integrated Catalytic Membrane Reactor for hydrogen production was studied by numerical simulation. The process is based on anhydrous NH₃ thermal dissociation inside a small size reactor (30 cm³), filled by a Ni/Al₂O₃ catalyst. The reaction is promoted by the presence of seven Pd coated tubular membranes about 203 mm long, with an outer diameter of 1.98 mm, which shift the NH₃ decomposition towards the products by removing hydrogen from the reaction area. The system fluid-dynamics was implemented into a 2D and 3D geometrical model. Ammonia cracking reaction over the Ni/Al₂O₃ catalyst was simulated using the Temkin-Pyzhev equation.Introductory 2D simulations were first carried out for a hypothetic system without membranes. Because of reactor axial symmetry, different operative pressures, temperatures and input flows were evaluated. These introductory results showed an excellent ammonia conversion at 550 °C and 0.2 MPa for an input flow of 1.1 mg/s, with a residual NH₃ of only a few ppm. 3D simulations were then carried out for the system with membranes. Hydrogen adsorption throughout the membranes has been modeled using the Sievert’s law for the dissociative hydrogen flux. Several runs have been carried out at 1 MPa changing the temperature between 500 °C and 600 °C to point out the conditions for which the permeated hydrogen flux is the highest. With temperatures higher than 550 °C we obtained an almost complete ammonia conversion already before the membrane area. The working temperature of 550 °C resulted to be the most suitable for the reactor geometry. A good matching between membrane permeation and ammonia decomposition was obtained for an NH₃ input flow rate of 2.8 mg/s. Ammonia reaction shift due to the presence of H₂ permeable membranes in the reactor significantly fostered the dissociation: for the 550 °C case we obtained a conversion rate improvement of almost 18%.     

Plasma-enhanced catalytic ammonia decomposition over ruthenium (Ru/Al2O3) and soda glass (SiO2) materials

Catalytic ammonia (NH₃) decomposition has been identified as a COx-free, sustainable hydrogen production method for fuel cell applications. In this study, the performance of plasma–catalyst-based NH₃ decomposition over ruthenium (Ru/Al₂O₃) and soda glass (SiO₂) catalytic materials at atmospheric pressure and ambient temperature was investigated. NH₃ decomposition reactions were conducted in a dielectric barrier discharge plasma plate-type reactor. NH₃ was fed into the plate catalytic microreactor at flow rates of 0.1–1 L/min and plasma voltages of 12–18 kV. Compared to plasma NH₃ decomposition without a catalyst, plasma–catalyst-based NH₃ decomposition showed a significant enhancement of the hydrogen production rate and energy efficiency. Furthermore, the hydrogen concentration results obtained over the Ru/Al₂O₃ catalyst were higher than those over the SiO₂ catalyst because Ru/Al₂O₃ possesses good electronic properties and exhibits high sensitivity to NH₃ decomposition. In addition, the resulting plasma heat enhanced the activation of the catalytic material, subsequently leading to an increase in the hydrogen production rate from NH₃. The maximum conversion rates were 85.65% and 84.39% for Ru/Al₂O₃ and SiO₂, respectively. Moreover, the energy efficiency of NH₃ decomposition over the Ru-based catalyst material was higher than that over the SiO₂ material. The presence of the catalyst active sites and plasma enhanced the mean electron energy, which could enhance the dissociation of NH₃. It can be concluded that the SiO₂ material can be utilised as a catalyst and that its combination with plasma accelerates the decomposition process of NH₃ and incurs a lower cost compared to Ru materials.     

Catalyst support effect on ammonia decomposition over Ni/MgAl2O4 towards hydrogen production

Ammonia is a prospective fuel for hydrogen storage and production, but its application is limited by the high cost of the catalysts (Ru, etc.) to decompose NH₃. Decomposing ammonia using non-precious Ni as catalysts can therefore improve its prospects to produce hydrogen. This work proposes several Ni/MgAl₂O₄ with the support properties tuned and investigates the support effect on the catalytic performance. Ni/MgAl₂O₄-LDH shows high NH₃ conversion (～88.7%) and H₂ production rate (～1782.6 mmol g^?1 h^?1) at 30,000 L. kg^?1 h^?1 and 600 °C, which is 1.68 times as large as that of Ni/MgAl₂O₄-MM. The performance remains stable over 30 h. The characterizations manifest that the high specific surface area of Ni/MgAl₂O₄-LDH can introduce highly dispersed Ni on the surface. Kinetics analysis implies promoted NH₃ decomposition reaction and alleviated H₂ poisoning for Ni/MgAl₂O₄-LDH. A roughly linear relationship is obtained by fitting the curves of dispersed Ni on the surface vs the reaction orders regarding H₂ and NH₃. This indicates that enhanced NH₃ decomposition performance can be ascribed to the strengthened NH₃ decomposition reaction and weakened H₂ poisoning by the highly dispersed Ni on the MgAl₂O₄-LDH surface. This work provides an opportunity to develop highly active and cost-effective catalysts to produce hydrogen via NH₃ decomposition.     

Life cycle net energy and global warming impact assessment for hydrogen production via decomposition of ammonia recovered from source-separated human urine

Decomposition of ammonia derived from source-separated human urine is a renewable approach for hydrogen production. Life cycle net energy analysis and global warming impact of scaled-up hydrogen production via this technique are studied in this paper. Ammonia decomposition processes, including fixed-bed reactors with Ru/Al₂O₃ and Ni/Al₂O₃ as catalyst options are simulated using the Aspen Plus software, and the results are compared with published data for validation. The life cycle net energy indicators are assessed for three scenarios of ammonia generation: conventional air stripping, microbial fuel cell, and electrochemical cell methods at a unit basis of 1000 kg of H₂ production. Results show that the microbial fuel cell process is more energy-efficient and emits lower greenhouse gases. The net energy ratio of the microbial fuel cell method is 1.38, and 1.12, for Ru/Al₂O₃ and Ni/Al₂O₃, respectively. A comparative assessment of ammonia generation and decomposition options for environmentally-benign hydrogen production is discussed.     

Improvement in ammonia synthesis activity on ruthenium catalyst using ceria support modified a large amount of cesium promoter

A supported ruthenium catalyst (Ru/Cs⁺/CeO₂) for ammonia synthesis is described which incorporates a large amount of a Cs⁺ promoter in a porous CeO₂ support to enhance the electron donation effect of the alkali promoter on the ruthenium catalyst. Optimization of the Ru and Cs⁺ promoter contents improves the ammonia synthesis rate to more than 4 times that of the benchmark catalyst (Cs⁺/Ru/MgO) at 350 °C and 0.1 MPa, and the ammonia synthesis rate is stable for 100 h. Introduction of the Cs⁺ promoter into the support before the Ru impregnation increases the particle size of the Ru catalyst. Despite a decrease in the number of active sites, the TOF of the catalyst is more than 50 times that of Ru (2 wt%)/CeO₂. CO adsorption measurements suggest an electron donating effect by the Cs⁺ promoter to ruthenium metal. Reaction order analysis indicates this is due to a mitigation of hydrogen poisoning.     

Ammonia as hydrogen carrier for transportation; investigation of the ammonia exhaust gas fuel reforming

In this paper we show, for the first time, the feasibility of ammonia exhaust gas reforming as a strategy for hydrogen production used in transportation. The application of the reforming process and the impact of the product on diesel combustion and emissions were evaluated. The research was started with an initial study of ammonia autothermal reforming (NH₃ – ATR) that combined selective oxidation of ammonia (into nitrogen and water) and ammonia thermal decomposition over a ruthenium catalyst using air as the oxygen source. The air was later replaced by real diesel engine exhaust gas to provide the oxygen needed for the exothermic reactions to raise the temperature and promote the NH₃ decomposition. The main parameters varied in the reforming experiments are O₂/NH₃ ratios, NH₃ concentration in feed gas and gas – hourly – space – velocity (GHSV). The O₂/NH₃ ratio and NH₃ concentration were the key factors that dominated both the hydrogen production and the reforming process efficiencies: by applying an O₂/NH₃ ratio ranged from 0.04 to 0.175, 2.5–3.2 l/min of gaseous H₂ production was achieved using a fixed NH₃ feed flow of 3 l/min. The reforming reactor products at different concentrations (H₂ and unconverted NH₃) were then added into a diesel engine intake. The addition of considerably small amount of carbon – free reformate, i.e. represented by 5% of primary diesel replacement, reduced quite effectively the engine carbon emissions including CO₂, CO and total hydrocarbons.     

Characterization of an ammonia decomposition process by means of a multifunctional catalytic membrane reactor

Ammonia decomposition was studied in a multifunctional catalytic membrane reactor filled with Ruthenium catalyst and equipped with palladium-coated membranes. To characterize the system we measured NH₃ conversion, H₂ yield and its partial pressure, the internal and external temperatures of the reactor shell and the electric consumption under several NH₃ flow and pressure conditions. Experimental results showed that the combined effect of Ruthenium catalyst and palladium membranes allowed the reaction to reach the equilibrium in all the conditions we tested. At 450 °C the ammonia conversion resulted the most stationary, while at 7 bar the hydrogen yield was almost independent of both the ammonia flow and temperature. In addition, the experimental system used in this work showed high values of NH₃ conversion and H₂ permeation also without heating the ammonia tank and therefore renouncing to control the feeding gas pressure. When ultra-pure hydrogen is needed at a distal site, a reactor like this can be considered for in situ hydrogen production.     

Oxygen vacancies and morphology engineered Co3O4 anchored Ru nanoparticles as efficient catalysts for ammonia borane hydrolysis

Developing efficient but facile strategies to modulate the catalytic activity of Ru deposited on metal oxides is of broad interest but remains challenging. Herein, we report the oxygen vacancies and morphological modulation of vacancy-rich Co₃O₄ stabilized Ru nanoparticles (NPs) (Ru/V_O-Co₃O₄) to boost the catalytic activity and durability for hydrogen production from the hydrolysis of ammonia borane (AB). The well-defined and small-sized Ru NPs and V_O-Co₃O₄ induced morphology transformation via in situ driving V_O-Co₃O₄ to 2D nanosheets with abundant oxygen vacancies or Co²⁺ species considerably promote the catalytic activity and durability toward hydrogen evolution from AB hydrolysis. Specifically, the Ru/V_O-Co₃O₄ pre-catalyst exhibits an excellent catalytic activity with a high turnover frequency of 2114 min^?1 at 298 K. Meanwhile, the catalyst also shows a high durability toward AB hydrolysis with six successive cycles. This work establishes a facile but efficient strategy to construct high-performance catalysts for AB hydrolysis.     

Single-step synthesized dual-layer hollow fiber membrane reactor for on-site hydrogen production through ammonia decomposition

On-site hydrogen production via catalytic ammonia decomposition presents an attractive pathway to realize H₂ economy and to mitigate the risk associated with storing large amounts of H₂. This work reports the synthesis and characterization of a dual-layer hollow fiber catalytic membrane reactor for simultaneous NH₃ decomposition and H₂ permeation application. Such hollow fiber was synthesized via single-step co-extrusion and co-sintering method and constitutes of 26 μm-thick mixed protonic-electronic conducting Nd_5.5Mo_0.5W_0.5O_11.25-δ (NMW) dense H₂ separation layer and Nd_5.5Mo_0.5W_0.5O_11.25-δ-Ni (NMW-Ni) porous catalytic support. This dual-layer NMW/NMW-Ni hollow fiber exhibited H₂ permeation flux of 0.26 mL cm⁻² min⁻¹ at 900 °C when 50 mL min⁻¹ of 50 vol% H₂ in He was used as feed gas and 50 mL min⁻¹ N₂ was used as sweep gas. Membrane reactor based on dual-layer NMW/NMW-Ni hollow fiber achieved NH₃ conversion of 99% at 750 °C, which was 24% higher relative to the packed-bed reactor with the same reactor volume. Such higher conversion was enabled by concurrent H₂ extraction out of the membrane reactor during the reaction. This membrane reactor also maintained stable NH₃ conversion and H₂ permeation flux as well as structure integrity over 75 h of reaction at 750 °C.     

Preparation of Ru–Cs catalyst and its application on hydrogen production by ammonia decomposition

Ammonia can be a hydrogen source for many applications including fuel cells. Using Ru or Cs–Ru as the catalyst, hydrogen is generated from ammonia by decomposition reaction. These catalysts are deposited on carbon powder by either chemical reduction or precipitation method in this study. Different carbon powder pre-treatment solutions and catalyst deposition conditions are evaluated. Nitric acid pre-treatment followed by precipitation at pH of 6 produces the highest catalyst loading from solution with given concentration of catalyst precursor. Hydrogen generation rate is measured at different catalyst compositions, ammonia inlet flow rates, decomposition temperatures, amount of catalyst packing, and ratio of Cs/Ru. The optimal condition for the ammonia decomposition reaction is Cs/Ru weight ratio at 3, ammonia inlet flow at 6 ml min⁻¹, reaction temperature at 400 °C. At this condition, the ammonia conversion rate reaches 90% and hydrogen generation rate reaches 29.8 mmol/min-g_cat.     

One-step synthesis of Ni/yttrium-doped barium zirconates catalyst for on-site hydrogen production from NH3 decomposition

On-site produced hydrogen from ammonia decomposition can directly fuel solid oxide fuel cells (SOFCs) for power generation. The key issue in ammonia decomposition is to improve the activity and stability of the reaction at low temperatures. In this study, proton-conducting oxides, Ba(Zr,Y) O_3-δ (BZY), were investigated as potential support materials to load Ni metal by a one-step impregnation method. The influence of Ni loading, Ba loading, and synthesis temperature, of Ni/BZY catalysts on the catalytic activity for ammonia decomposition were investigated. The Ni/BZY catalyst with Ba loading of 20 wt%, Ni loading of 30 wt%, and synthesized at 900 °C attained the highest ammonia conversion of 100% at 600 °C. The kinetics analysis revealed that for Ni/BZY catalyst, the hydrogen poisoning effect for ammonia decomposition was significantly suppressed. The reaction order of hydrogen for the optimized Ni/BZY catalyst was estimated as low as ?0.07, which is the lowest to the best of our knowledge, resulting in the improvement in the activity. H₂ temperature programmed reduction and desorption analysis results suggested that a strong interaction between Ni and BZY support as well as the hydrogen storage capability of the proton-conducting support might be responsible for the promotion of ammonia decomposition on Ni/BZY. Based on the experimental data, a mechanism of hydrogen spillover from Ni to BZY support is proposed.     

Preparation of a novel bimodal catalytic membrane reactor and its application to ammonia decomposition for COx-free hydrogen production

A novel bimodal catalytic membrane reactor (BCMR) consisting of a Ru/γ-Al₂O₃/α-Al₂O₃ bimodal catalytic support and a silica separation layer was proposed. The catalytic activity of the support was successfully improved due to enhanced Ru dispersion by the increased specific surface area for the γ-Al₂O₃/α-Al₂O₃ bimodal structure. The silica separation layer was prepared via a sol–gel process, showing a H₂ permeance of 2.6 × 10⁻⁷ mol Pa⁻¹ m⁻² s⁻¹, with H₂/NH₃ and H₂/N₂ permeance ratios of 120 and 180 at 500 °C. The BCMR was applied to NH₃ decomposition for CO_x-free hydrogen production. When the reaction was carried out with a NH₃ feed flow rate of 40 ml min⁻¹ at 450 °C and the reaction pressure was increased from 0.1 to 0.3 MPa, NH₃ conversion decreased from 50.8 to 35.5% without H₂ extraction mainly due to the increased H₂ inhibition effect. With H₂ extraction, however, NH₃ conversion increased from 68.8 to 74.4% due to the enhanced driving force for H₂ permeation through the membrane.     

Direct methane cracking using a mixed conducting ceramic membrane for production of hydrogen and carbon

The direct cracking of methane can be used to produce CO_x and NO_x-free hydrogen for proton exchange membrane fuel cells. Recent studies have been focused on enhancing the hydrogen production using the direct thermocatalytic decomposition of methane as an attractive alternative to the conventional steam reforming process. We present the results of a systematic study of methane direct decomposition using a mixed conducting oxide, Y-doped BaCeO₃, membrane. A dense disk-shaped BaCe_0.85Y_0.15O₃ membrane was successfully prepared and covered with Pd film, as the catalyst for the methane decomposition. For the methane thermocatalytic decomposition, the methane gas was employed as reactant on the membrane side with a pressure of 10² kPa and rate of 70 ml/min at the reaction temperatures of 600, 700, and 800 °C. The hydrogen was selectively transported through the mixed conducting oxide membrane to the outer side. In addition, the carbon, which is a by-product after methane decomposition, showed the morphologies of sphere-shaped nanoparticles and the transparent sheets.     

Highly efficient Co/NC catalyst derived from ZIF-67 for hydrogen generation through ammonia decomposition

Small-size cobalt nanoparticles (NPs) distributed on nitrogen doped carbon support (Co/NC-X) were prepared by pyrolysis of ZIF-67 at various temperatures (X = 500, 600,700 and 800 °C) in nitrogen atmosphere and utilized as catalysts for hydrogen production through ammonia decomposition. Characterizations of the catalysts including XRD, HRTEM, XPS, H₂-TPR, CO₂-TPD, etc., were conducted for structure analysis. The N–C plate obtained from pyrolysis was coated with Co NPs to hinder its aggregation, which made the Co NPs dispersed evenly and increased their dispersion. The calcination temperature and the strong base of the support can adjust the strength of Co–N bond. The activity of the Co/NC-X catalysts is attributed to the high content of Co⁰ and the moderate Co–N bond strength. The ammonia decomposition activity of Co/NC-X catalysts in this paper is higher than many reported Co-based catalysts. Co/NC-600 catalyst demonstrates an ammonia conversion of 80% at 500 °C with a space velocity of 30,000 ml g_cat^?1 h^?1, corresponding to a hydrogen production rate of 26.8 mmol H₂ g_cat^?1 min^?1. The work provides insight for the development of highly active cobalt-based catalysts for hydrogen production through ammonia decomposition.     

Hydrogen production from hydrolysis of ammonia borane with limited water supply

Effect of limited water supply to hydrolysis of ammonia borane for hydrogen evolution is studied over the cases in which the initial molar ratio of water to ammonia borane (H₂O/AB) is set at 1.28, 2.57 and 4.50. The conversion efficiency of ammonia borane to hydrogen is estimated from the accumulated volume of produced hydrogen gas and the quantitative analysis of hydrolysate by solid-state ¹¹B NMR. Characteristics of hydrogen evolution are significantly influenced by both water dosage and injection rate of water. In the case that water is a limiting agent, namely, H₂O/AB = 1.28, less hydrogen is produced than that predicted stoichiometrically. In contrast, conversion efficiency of ammonia borane reaches nearly 100% for the case with H₂O/AB = 4.50. Injection rate of water to ammonia borane also affect profoundly the produced volume and production rate of hydrogen, if water is used as a limiting agent in the hydrolysis of ammonia borane. Nonetheless, boric acid and metaboric acid are found to be the dominant products in the hydrolysate from XRD, FT-IR and solid-state ¹¹B NMR analysis. The hydrogen storage capacity using limited water supply in this work could reach as high as about 5.33 wt%, based on combined mass of reactants and catalyst.     

Ru-Ba/ANF catalysts for ammonia decomposition: Support carbonization influence

The study of ruthenium catalysts for ammonia decomposition on carbonized and non-carbonized Al₂O₃ nanofibers (ANF) showed that the activity of catalysts with carbonized supports (ANFC) was 2–3 times higher compared to non-carbonized ones. Thus, on Ru/ANFC and Ru/ANF the release of hydrogen reached 133.5 and 34.7 mmol H₂/(min·g_cat), respectively, whereas on Ru-Ba^Ac/ANFC and Ru-Ba^Ac/ANF, only 118.8 and 58.6 mmol H₂/(min·g_cat), respectively. On the average, the activation energy of ammonia decomposition on ANFC-supported catalysts is 15 kJ/mol lower than that value for ANF-supported catalysts. According to TEM data, Ru particles on ANFC are larger than on ANF, but are more evenly distributed. An increase in the activity of the catalyst correlates with a change in the electronic state of the active component. XPS data for Ru indicate a shift in the binding energy towards lower values when going from ANF to ANFC.     

Hydrogen production via catalytic pulsed plasma conversion of methane: Effect of Ni–K2O/Al2O3 loading,applied voltage,and argon flow rate

Despite industrial application of methane as an energy source and raw material for chemical manufacturing, it is a potent heat absorber and a strong greenhouse gas. Evidently reduction of methane emission especially in the natural gas sector is essential. Methane to hydrogen conversion through non-thermal plasma technologies has received increasing attention. In this paper, catalytic methane conversion into hydrogen is experimentally studied via nano-second pulsed DBD plasma reactor. The effect of carrier gas flow, applied voltage, and commercial Ni–K₂O/Al₂O₃ catalyst loading on methane conversion, hydrogen production, hydrogen selectivity, discharge power, and energy efficiency are studied. The results showed that in the plasma alone system, the highest methane conversion and hydrogen production occurs at argon flow rate of 70 mL/min. Increase in the applied voltage increases the methane conversion and hydrogen production while it decreases the energy efficiency. Presence of 1 g Ni–K₂O/Al₂O₃ catalyst shifts the optimum voltage for methane conversion and hydrogen production to 8 kV, reduces the required power, and increases the energy efficiency of the process. Finally in the catalytic plasma mode the optimum process condition occurs at the argon flow rate of 70 mL/min, applied voltage of 8 kV, and catalyst loading of 6 g. Compared with the optimum condition in the absence of catalyst, presence of 6 g Ni–K₂O/Al₂O₃ catalyst increased the methane conversion, hydrogen production, hydrogen selectivity and energy efficiency by 15.7, 22.5, 7.1, and 40% respectively.     

Mo-doped Ni-based catalyst for remarkably enhancing catalytic hydrogen evolution of hydrogen-storage materials

Ni-based alloys are considered as the efficient catalyst for hydrogen-storage materials decomposition. Herein, we applied an in-situ melt-quenching method to dope Mo in Ni-based alloy for catalytic hydrogen evolution from hydrogen-storage materials. Importantly, Mo doped Ni-based catalyst exhibits more than 6 times higher TOF value than that of pure Ni both in AB hydrolysis and hydrazine decomposition, because Mo acts as an electron donor to improve the reducibility of Ni. Hydrogen evolution kinetics were studied over a range of temperatures (303–353 K) and initial feed concentrations (catalyst/hydrogen-storage materials (wt/wt) ratios = 0.2–10). Under optimal reaction conditions, the H₂ evolution rate reaches 1.92 mol H₂/(mol_cat min) and 0.05 mol H₂/(mol_cat min) in the hydrolysis of ammonia borane and decomposition of hydrazine, which are 6.42 and 6.44 times higher than undoped Ni catalyst, respectively. And the apparent activation energy of ammonia borane hydrolysis and hydrazine decomposition were evaluated to be 26.66 ± 3.31 kJ/mol and 40.01 ± 3.38 kJ/mol, respectively.     

Energy and exergy analysis of hydrogen production from ammonia decomposition systems using non-thermal plasma

In the current study, the energy and exergy efficiencies of three hydrogen production systems from ammonia decomposition using dielectric barrier discharge plasma (DBD) were comparatively evaluated. The hydrogen gas was separated in a cylindrical plasma membrane reactor (PMR) using the Pd–Cu40% membrane with a thickness of 20 μm. The pre-catalytic reactor (CR) is added to the second system (CR-PMR), additionally, the CR is filled with the catalytic material type of 2%Ru/Al₂O₃ and the CR temperature is raised to 450 °C. Furthermore, the zeolite material type of SA-600 A was added to the PMR in the third H₂ production system (PMR) to enhance the hydrogen permeation through the Pd–Cu membrane. The hydrogen production rate was enhanced by combining the plasma and zeolite material in the third system (CR-CPMR). Moreover, the maximum obtained hydrogen production rates were 2.66, 81.6, and 96.6% in PMR, CR-PMR, and CR-CPMR or catalytic PMR, respectively. Also, it was observed that the energy efficiency increased by adding the CR to the system, while, the exergy efficiency values of all ammonia decomposition systems were still low due to the effect of system irreversibility. Additionally, the maximum energy efficiencies values were 0.8, 16.1, 44.1%, while the maximum exergy efficiencies values were 0.156, 4.91, and 6.344% for PMR, CR-PMR, and CR-CPMR, respectively. The exergy destruction rate of all NH₃ decomposition systems was still high although using the modified systems. The depletion factor is enhanced with the feeding ammonia flow rate increased while the sustainability index decreased at the same flow rates. Moreover, it was seen that the depletion factor results of PMR only were higher than other systems due to the exergy destruction rate was high.