Dynamic hydrogen production from ethanol steam‐reforming reaction on NixMoy/SBA‐15 catalytic system

This study examined the effects of advanced bimetallic catalytic species of Ni and Mo on hydrogen production from ethanol steam reforming. Ni_xMo_y/SBA‐15 exhibited significantly higher ethanol steam‐reforming activity at mild temperatures than monometallic Ni/SBA‐15; the highest activity was achieved using the Ni_0.95Mo_0.05/SBA‐15 catalyst. H₂ production and ethanol conversion were maximized at 70–87% and 90–92%, respectively, over the temperature range of 500 to 800 °C with an EtOH : H₂O ratio of 1:3 and a gas hourly space velocity of 3000 h^?1. This highlights the synergy between the Ni and Mo loading on SBA‐15 during ethanol steam reforming through the inhibition of Ni particle agglomeration and the consequent decrease in catalytic deactivation. In the proposed mechanism for ethanol steam reforming, Mo oxide promotes CH₄‐steam reforming at lower temperatures and depresses the CO‐water gas shift reaction. Overall, hydrogen production is significantly higher over Ni_xMo_y/SBA‐15 than over monometallic Ni/SBA‐15 despite the evolution of CO gas. Copyright © 2014 John Wiley & Sons, Ltd.     

Plasma steam methane reforming (PSMR) using a microwave torch for commercial-scale distributed hydrogen production

Although large-scale hydrogen production through conventional steam methane reforming (SMR) is available at an affordable cost, there is a shortage of hydrogen pipeline infrastructure between production plants and fueling stations in most places where hydrogen is needed. Due to the difficulties of transporting and storing hydrogen, onsite hydrogen production plants are desirable. Microwave plasma torch-based methods are among the most promising approaches to achieving this goal.The plasma steam methane reforming (PSMR) method discussed here has many benefits, including a high energy yield, a small carbon footprint, real-time fueling because of the short start-up time (<10 min), and the absence of expensive metal-based catalysts. Methane reforming and water gas shift reaction (WGSR) co-occur in the method advanced without a separate WGSR to achieve a high H₂ yield.This study examines an experimental investigation of commercial-scale hydrogen production through PSMR utilizing a microwave torch system. The optimum results obtained showed that the hydrogen production rate was 2247 [g(H₂)/h], and energy yield was 70 [g(H₂)/kWh] of the absorbed microwave power. An assessment of the results indicated a similar trend to that of simulated data (ASPEN Plus). The experimental results presented in this paper demonstrate the potential of a catalyst-free PSMR for commercial-scale hydrogen production.     

Hydrogen production on Pd0.01Zn0.29Mg0.7Al2O4 spinel catalyst by low temperature ethanol steam reforming reaction

This study investigated the low-temperature ethanol steam reforming (LTESR) performance of a Pd_0.01Zn_0.29Mg_0.7Al₂O₄ catalyst. Although it was present in a very small amount, the Pd component was the key to the partial CO-water gas shift and CO-methanation that, eventually, helped to increase the yield of H₂ during LTESR. An 80% yield of H₂ was maintained even after 30 h at 450 °C on the Pd_0.01Zn_0.29Mg_0.7Al₂O₄ catalyst with 100% ethanol conversion. Furthermore, the spinel structure of the catalyst remained unchanged after the reaction, and there was no increase in size owing to particle-to-particle aggregation. This study demonstrated that the Pd and Zn components could be stably located in the spinel structure of the MgAl₂O₄ with no sintering of the particles. Moreover, the oxygen transfer capacity of the MgAl₂O₄ spinel structure helped maintain the catalytic performance for long time periods by transferring oxygen to the reduced catalytic metal species (Zn or Pd) during the reaction, even though this induced oxygen defects in the spinel crystal. Overall, improved catalyst activity and an extended catalyst lifespan were observed.     

Study on a catalytic membrane reactor for hydrogen production from ethanol steam reforming

Ethanol steam reforming in a membrane reactor with catalytic membranes was investigated to achieve important aims in one process, such as improvement in ethanol conversion and hydrogen yield, high hydrogen recovery and CO reduction. In order to confirm the efficiency of reaction and CO reduction, an ethanol reforming-catalytic membrane reactor with water–gas shift reaction (ECRW) in the permeate side was compared with a conventional reactor (CR) and an ethanol reforming-catalytic membrane reactor (ECR). In comparison with the CR, ethanol conversion improvement of 11.9–19% and high hydrogen recovery of 78–87% were observed in the temperature range of 300–600 °C in the ECRW. Compared with CR and ECR, the hydrogen yield of ECRW increased up to 38% and 30%, respectively. Particularly, the ECRW showed higher hydrogen yield at high temperature, because Pt/Degussa P25 loaded in the permeate side showed catalytic activity for the methane steam reforming as well as WGS reaction. Moreover, CO concentration was reduced under 1% by the WGS reaction in the permeate side in the temperature range of 300–500 °C.     

Hydrogen production from ethanol steam reforming over Ni/SiO2 catalysts: A comparative study of traditional preparation and microwave modification methods

Four silica‐supported nickel catalysts with Ni content of 10 wt% were prepared by impregnation and coprecipitation methods with or without microwave‐assisted calcination. The prepared catalysts were characterized by some techniques (BET, XRD, TEM, XPS, H₂‐TPR, etc.) and evaluated with respect to steam reforming of ethanol (SRE) for hydrogen production. The results show that the prepared Ni/SiO₂ catalysts are all very active and selective for SRE. The high activity of the four catalysts may benefit from their high specific areas and the good dispersion of active components on the carrier. The rate of carbon deposition decreases with reaction temperature especially below 450 °C. The maximum hydrogen yield of 4.54 mol H₂/mol EtOH‐reacted can be obtained over the Ni/SiO₂ catalyst by the microwave‐assisted coprecipitation method at a reaction temperature of 600 °C, EtOH/H₂O molar ratio of 1:12, liquid hourly space velocity of 11.54 h^?1 and time on stream within 600 min. The Ni/SiO₂ catalysts with microwave modification exhibits better performances of hydrogen production, stability and resistance to carbon deposition than that without microwave modification preparation, which is mainly attributed to that the microwave‐assisted treatment can decrease the catalyst acidity and enhance the interaction between metal support. Copyright © 2013 John Wiley & Sons, Ltd.     

Efficient H2 production via membrane-assisted ethanol steam reforming over Ir/CeO2 catalyst

Ethanol steam reforming in membrane reactors is a promising route for decentralized H₂ production from biomass because H₂ yield can be greatly enhanced due to the equilibrium shift triggered by instantaneous H₂ extraction. Here a highly active Ir/CeO₂ catalyst has been combined with ca. 4 μm thin Pd membranes employing a 6:1 steam/ethanol feed between 673 K and 873 K at reforming pressures up to 1.8 MPa. The H₂ yield reached 94.5% at 873 K and 1300 kPa due to the separation of 91.8% H₂ whereas H₂ yield was limited to 28.9% without membrane. At lower temperatures and pressures sweep gas was needed at the membranes' permeate side for efficient H₂ generation since the H₂ partial pressure remains equilibrium-limited on the reaction side. Furthermore, the H₂ yield improved from 63.0% to 84.7% at 773 K, 1500 kPa and sweep-to-feed flow ratio 0.5 when the distance between membrane and reactor wall was shortened by ca. 30%. Thus, external H₂ diffusion towards the membrane has a large impact on membrane reactor performance pointing towards microstructured membrane reactors as optimum devices for sustainable H₂ production from biomass.     

Continuous high-purity hydrogen production by sorption enhanced steam reforming of ethanol over modified lithium silicate

Sorption-enhanced steam reforming of ethanol (SE-SRE) with in-situ CO₂ removal is an environmentally friendly and sustainable approach for hydrogen production. Researches on continuous production of high-purity H₂ by SE-SRE over the modified Li₄SiO₄ sorbent were conducted using two parallel reactor in this work. The low cost Li₄SiO₄ derived from rice husk ash (RHA) is a promising high-temperature CO₂ sorbent. However, the poor adsorption kinetics of RHA-Li₄SiO₄ sorbent at low CO₂ concentration is the major challenge. The metallic elements (K, Ca, Al, Mg) were employed to modify the RHA-Li₄SiO₄ for efficient CO₂ capture. The developed sorbents were characterized and tested to study the role of dopants on the crystal, textural, microstructure and CO₂ adsorption kinetics and cyclic stability. Results indicated that K doping effectively inhibited the growth of crystal aggregation and resulted in a fluffy morphology with abundant pores and higher specific surface area, while the addition of Ca, Al and Mg formed a nubby structure with larger particle size. K-doped RHA-Li₄SiO₄ exhibited the best CO₂ uptake properties and the optimal K doping molar content was 0.02 with the maximum capture capacity of 34.16 wt%, which is higher than 27.1 wt% of pure RHA-Li₄SiO₄. Then, the effect of operating conditions on the enhancement behaviors was considered in the SE-SRE system. High-purity H₂ (above 96%) was achieved by coupling K(0.02)/RHA-Li₄SiO₄ sorbent with Ni-based catalyst under the optimum condition (T: 525 °C, liquid hourly space velocity: 0.9 mL/(g·h), sorbent/catalyst: 4 and steam/carbon: 8.0). The adsorption activity of K(0.02)/RHA-Li₄SiO₄ maintained at a high level in ten SE-SRE/regeneration cycles. Finally, a scheme including two parallel fixed-bed reactors was designed and operated periodically for continuous production of high-purity H₂. The reaction switching time was shown to depend strongly on the pre-breakthrough time and operating conditions. As the reaction switching time was 40 min, the products were always only H₂ and CH₄ (no CO and CO₂ appear) and the H₂ purity remained above 90% during 400 min, confirming high purity hydrogen stream can be obtained continuously.     

Hydrogen production by steam reforming of ethanol over Co/CeO2 catalysts: Effect of cobalt content

The Co/CeO₂ catalysts obtained by co-precipitation method were used in the steam reforming of ethanol (SRE). The influence of cobalt active phase content (15–29 wt%), the reaction temperature (420–600 °C) and H₂O/EtOH molar ratio (12/1 and 6/1) were examined. The physicochemical characterization revealed that the cobalt content of the catalyst influences the metal-support interaction which results in catalyst performance in SRE process. The differences between catalytic properties of the Co/CeO₂ catalysts with different metal loading in SRE process decayed at 500 °C for H₂O/EtOH = 12/1. The best performance among the tested catalysts showed the 29Co/CeO₂ catalyst with the highest cobalt content, exhibiting the highest ethanol conversion, selectivity to two most desirable products and the lowest selectivity to by-products in comparison with catalysts containing smaller amount of metal. Its catalytic properties results probably from its unique physicochemical properties, i.e this catalyst contains large amount of cobalt but the metal crystallites are relatively small. Regardless cobalt content, an increase in the water-to-ethanol molar ratio in the feed increased the concentration of hydrogen an carbon dioxide and decreased formation of carbon monoxide, acetone, aldehyde and ethylene.     

Sorption enhanced steam reforming of ethanol for hydrogen production,over Mg/Al hydrotalcites modified with K

Sorption-enhanced ethanol steam reforming is an interesting alternative, to produce high purity H₂. In this study, potassium promoted hydrotalcites are compared for sorption-enhanced ethanol steam reforming reaction under cyclic operation, performing sorbent regeneration at reaction temperature which is a great advantage to reduce process energy requirements. It is found that potassium promoted hydrotalcites have higher CO₂ sorption capacity compared to unpromoted ones, due to the higher concentration of intermediate and strong basic sites. The hydrotalcite modified with 15 wt% potassium shows the best performance on multicyclic CO₂ sorption-desorption (sorption capacity = 0.167 mol_CO2/kgsorbent). Therefore, there is an optimum loading of potassium, for which the opposite effects of reduction in surface area and enhanced basicity are balanced. Finally, potassium promoted hydrotalcites are tested under cyclical ethanol reforming process with simultaneous adsorption of CO₂ followed by regeneration in N₂ at reaction temperature (500 °C). At short reaction times (<5 min), H₂ purities higher than 95% are achieved, with CO₂ purities near 0%.     

Cost‐competitive methane steam reforming in a membrane reactor for H2 production: Technical and economic evaluation with a window of a H2 selectivity

Techno‐economic viability studies of employing a membrane reactor (MR) equipped with H₂ separation membranes for methane steam reforming (MSR) were carried out for H₂ production in Korea using HYSYS®, a well‐known chemical process simulator, including economic analysis based on itemized cost estimation and sensitivity analysis (SA). With the reaction kinetics for MSR reported by Xu and Froment, the effect of a wide range of H₂ selectivity (10‐10,000) on the performance in an MR was investigated in this study. Because of the equilibrium shift owing to the Le Chatelier's principle, great performance of enhancement of methane conversion ( ) and H₂ yield and reaction temperature reduction was observed in an MR compared with a packed‐bed reactor (PBR). A window of a H₂ selectivity from 100 to 300 is proposed as a new criterion for better MR performance of MSR depending on potential applications from in‐depth analysis of and H₂ yield enhancements, a H₂ purity, and temperature reduction. In addition, economic analysis to evaluate the feasibility of an MR technology for MSR was carried out focusing on a levelized cost of H₂ based on itemized cost estimation of capital and operating costs as well as SA. Techno‐economic assessment showed 36.7% cost reduction in an MR compared with a PBR and revealed that this MR technology can be possibly opted for a cost‐competitive H₂ production process for MSR.     

Theoretical study of hydrogen production by ethanol steam reforming: Technical evaluation and performance analysis of catalytic membrane reactor

Ethanol steam reforming over a Co/Al₂O₃ catalyst was studied theoretically in a catalytic PdAg membrane reactor (CMR). A mathematical model has been developed to elucidate the behavior of CMR by taking into account the chemical reactions, heat and mass transfer phenomena. The effect of operating parameters on the performance of CMR has been evaluated in terms of ethanol conversion, hydrogen recovery and hydrogen yield. The results revealed the high performance of this configuration is related to the continuous removal of hydrogen from the retentate side, shifting the reaction equilibrium towards hydrogen formation. Sensitivity analysis of operating parameters indicate that ethanol conversion is favored at higher temperatures, pressures, sweep ratios and feed molar ratios. Moreover, increasing the feed molar ratio enhances the ethanol conversion, and decreases the hydrogen recovery due to reduction of partial pressure of hydrogen and consequently decreasing the driving force for the hydrogen permeation through the membrane.     

Development of a Fe/Mg-bearing metallurgical waste stabilized-CaO/NiO hybrid sorbent-catalyst for high purity H2 production through sorption-enhanced glycerol steam reforming

In this work, a Fe/Mg-bearing metallurgical waste (upgraded slag oxide, UGSO) was, for the first time, investigated as a stabilizer for increasing the cyclic stability of CaO-based sorbents. The sorbents were prepared through the wet mixing of the ball-milled UGSO particles with the limestone-derived calcium citrate under sonication. The sorption capacity of samples containing different waste loadings (5, 10, 15, and 25 wt%) was studied for 18 carbonation/regeneration cycles under conditions similar to the sorption-enhanced glycerol steam reforming process. A significant improvement of the cyclic stability was observed for all doped sorbents; however, the sample with 10 wt% UGSO showed the highest sorption capacity among all tested samples. This optimum sorbent was further used to synthesize a UGSO stabilized CaO–NiO hybrid sorbent-catalyst material (20 wt% NiO loading), whose performance was tested in sorption-enhanced steam reforming of glycerol. A H₂ purity of around 95% was obtained in the pre-breakthrough period that lasted for about 30 min. In summary, the results showed a better stability of UGSO stabilized sorbents compared to pure CaO and a good performance of the CaO-UGSO10/NiO sorbent-catalyst hybrid material in the sorption-enhanced reforming process.     

Hydrogen production by ethanol steam reforming over M-Ni/sepiolite (M = La,Mg or Ca) catalysts

Ethanol steam reforming (ESR) is a technology of great promise for hydrogen production but designing highly efficient, green and inexpensive Ni-based catalysts for inhibiting metal sinter and carbon deposition and increasing catalyst activity and stability is still a key challenge. In this paper, the M-Ni/Sepiolite catalysts (M-Ni/SEP, M = La, Mg or Ca) were synthesized using a hydrothermal-assisted impregnation method. The results from characterizations such as N₂ adsorption-desorption, XRD, H₂-TPR, XPS, HRTEM and NH₃/CO₂-TPD showed that La, Mg and Ca promoters can facilitate the dispersion and exposure of Ni⁰ active sites, enhance the metal-support interaction and modify surface acid/alkaline sites. Furthermore, the results of catalyst activity tests in ESR demonstrated that the Ca–Ni/SEP catalyst exhibited the highest carbon conversion of 95% and hydrogen yield of 65%, attributed to the small mean Ni particle size, strong metal-support interaction, abundant surface Ni⁰ active sites and modified surface alkaline/acid sites. According to the carbon deposition analyses, it was observed in Ca–Ni/SEP that the carbon deposition amount was evidently decreased, and the graphitic degree of coke was increased due to the increased metal site amount.     

Hydrogen production from steam reforming of ethanol using a ceria-supported iridium catalyst: Effect of different ceria supports

Catalytic activity of a ceria-supported Iridium (Ir/CeO₂) catalyst was investigated for steam reforming of ethanol within a temperature range of 300–500 °C. Three types of ceria were chosen to prepare the catalyst: commercial [assigned as CeO₂(C)] and prepared [using a simple reduction–oxidation method, CeO₂(R), and another combined with ultrasonic irradiation, CeO₂(U)] ceria. The Ir/CeO₂ catalyst with Ir loading of 2 wt.% was prepared by deposition–precipitation using iridium chloride (IrCl₃) as a precursor at 75 °C and pH = 9 (adjusted with 0.25 M Na₂CO₃). Catalytic activities toward the steam reforming of ethanol (SRE) were tested in a fixed-bed reactor. In order to better understand the effect of activation conditions of a catalyst on the reforming of ethanol, reduction pretreatment at 200 and 400 °C (assigned as H₂ and H₄) were conducted. The results indicated that only less sintering influences the catalytic activities for high temperature reduction. The ethanol conversion approached completion around 450 °C via reduction pretreatment for Ir/CeO₂(U) and Ir/CeO₂(C) samples under H₂O/EtOH molar ratio of 13 and 22,000 h⁻¹ GHSV. Not only was a high dispersion of both catalysts present but also no impurities (e.g., boron) interfered with the catalytic activities. The hydrogen yield (H₂ mole/EtOH mole) exceeds 5.0 with less content of CO and CH₄ (<2%).     

Simulation and multi‐objective optimization of a fixed bed catalytic reactor to produce hydrogen using ethanol steam reforming

A mathematical model is developed for a fixed bed catalytic reactor to produce hydrogen using ethanol steam reforming in the presence of a Ni (II)‐Al (III)‐LDH catalyst. The simulation of the reactor has been carried out using the ode23s module of MATLAB (version 2010a) based on a mechanistic kinetic model (Langmuir‐Hinshelwood approach) with proven reaction kinetics. There is a confusion regarding the values of the kinetic parameters even though earlier workers have used the same experimental data and the same model equations. The values of the model parameters obtained using two different curve‐fitting techniques, the generalized reduced gradient (GRG) algorithm and a derivative‐free approach based on the simplex method, were different. This leads to differences in the agreement of model predictions vs experimental results. A more powerful and recent technique, genetic algorithm (GA), has been used to resolve this problem by minimizing a sum‐of‐square errors (SSE). Our tuned model parameters gave good agreement with experimental data. An SSE value of the order of 10^?4 is obtained in the present study over the SSE values of the order of 10^?2 obtained from earlier studies. Using this tuned model, multi‐objective optimization (MOO) of an isothermal fixed bed ESR reactor has been carried out using NSGA‐II to achieve the maximum hydrogen mole fraction in the product gas while simultaneously minimizing the mole fractions of the greenhouse gases, CO + CO₂. The maximum theoretical mole fraction of hydrogen obtained is 0.088 at 911.86 K vs 0.080 at 923 K, as observed experimentally. The more recent jumping gene adaptation of NSGA‐II, namely, NSGA‐II‐JG, was also tried to check if it can give more rapid convergence to the Pareto set. It is found that the present problem is far too simple, and the advantage of the JG adaptation is small.     

Hydrogen production by ethanol steam reforming: Effect of the synthesis parameters on the activity of Ni/TiO2 catalysts

Ethanol steam reforming is an attracting process to produce hydrogen in a sustainable way. In this work the performance of Ni/TiO₂ catalysts in ethanol steam reforming was studied. In particular, the effect of the synthesis procedure on the properties of the catalysts and on their activity was deeply investigated. On the basis of the experimental results, it was evidenced that TiO₂-supported Ni systems are very sensitive to the synthesis parameters. We found that a proper thermal activation by calcination at 800 °C allows to obtain stable catalysts by means of strong interactions between the active phase and the support, preserving the catalyst from sintering phenomena. Nevertheless, the synthesis conditions must be properly tuned in order to prevent Ni incorporation in scarcely reducible structures which would depress catalytic activity.     

Novel hydrogen‐rich gas production by steam gasification of biomass in a research‐scale rotary tubular helical coil gasifier

The concept of biomass steam gasification offers platform for production (i) of hydrogen, (ii) hydrocarbons and (iii) value added chemicals. Majority of these developments are either in nascent or in pilot/demonstration stage. In this context, there exists potential for hydrogen production via biomass steam gasification. Gaseous products of biomass steam gasification consist of large percentage of CO, CH₄ and other hydrocarbons, which can be converted to hydrogen through water‐gas‐shift reaction, steam reforming and cracking respectively. Although there are many previous research works showing the potential of production of hydrogen from biomass in a two stage process, challenges remain in extended biomass and char gasification so as to reduce the amount of carbon in the residual char as well as improve conversion of heavy hydrocarbon condensates to hydrogen rich gas. In the current work, the characteristics of biomass steam gasification in an in‐house designed rotary tubular helical coil reactor at temperatures less than 850 °C, in the presence of superheated steam, were presented. The objectives were to obtain high carbon conversion in the primary biomass steam gasification step (upstream) and high product gas yield and hydrogen yield in the secondary fixed bed catalytic step (downstream). The influence of temperature, steam‐to‐biomass ratio and residence time on product gas yield in the rotary tubular helical coil gasifier was studied in detail using one of the abundantly available biomass sources in India‐rice husk. Further, enhancement of product gas yield and hydrogen yield in a fixed bed catalytic converter was studied and optimized. In the integrated pathway, a maximum gas yield of 1.92 Nm³/kg moisture‐free biomass was obtained at a carbon conversion efficiency of 92%. The maximum hydrogen purity achieved under steady state conditions was 53% by volume with a hydrogen yield of 91.5 g/kg of moisture‐free biomass. This study substantiates overall feasibility of production of high value hydrogen from locally available biomass by superheated steam gasification followed by catalytic conversion. Copyright © 2016 John Wiley & Sons, Ltd.     

Differential evolution (DE) strategy for optimization of methane steam reforming and hydrogenation of nitrobenzene in a hydrogen perm‐selective membrane thermally coupled reactor

In this work, a thermally coupled membrane reactor is proposed for methane steam reforming and hydrogenation of nitrobenzene. The steam reforming process is carried out in the assisted membrane surface of the endothermic side, while the hydrogenation reaction of nitrobenzene to aniline is carried out on the other membrane surface of the exothermic side. The differential evolution (DE) strategy is applied to optimize this reactor considering nitrobenzene and methane conversion as the main objectives. The co‐current mode is investigated in this study, and the achieved optimization results are compared with those of conventional steam reformer reactor operated under the same feed conditions. The optimum values of feed temperature of exothermic side, feed molar flow rate of nitrobenzene, the steam‐to‐nitrobenzene molar ratio and the hydrogen‐to‐nitrobenzene molar ratio are determined during the optimization process. The simulation results show that the methane conversion and consequently hydrogen recovery yield are increased by 39.3% and 1.57, respectively, which contribute to aniline production with 27.3% saving in hydrogen supply from external and a reduction in environmental problems due to 100% nitrobenzene conversion. The optimization results justify the feasibility of coupling these reactions. Experimental proof‐of‐concept is needed to establish the validity and safe operation of the novel reactor. Copyright © 2012 John Wiley & Sons, Ltd.     

Effect of Co,Fe and Rh addition on coke deposition over Ni/Ce0.5Zr0.5O2 catalysts for steam reforming of ethanol

Ni-based monometallic and bimetallic catalysts (Ni, NiRh, NiCo and NiFe) supported on Ce_0.5Zr_0.5O₂ support were evaluated on the steam reforming of ethanol (SRE) performance. The supports of Ce_0.5Zr_0.5O₂ composite oxide was prepared by co-precipitation method with Na₂CO₃ precipitant and assigned as CeZr(N). The monometallic catalyst was prepared by incipient wetness impregnation method and assigned as Ni/CeZr(N). The bimetallic catalysts were prepared by co-impregnation method to disperse the metals on the CeZr(N) support and assigned as NiM/CeZr(N). All samples were characterized by using XRD, TPR, BET, EA and TEM techniques at various stages of the catalyst. The results indicated that the facile reduction and smaller particle size of Ni/CeZr(N) (T₉₉ = 300 °C) and NiRh/CeZr(N) (T₉₉ = 250 °C) catalysts were preferential than the NiFe/CeZr(N) (T₉₉ = 325 °C) and NiCo/CeZr(N) (T₉₉ = 375 °C) catalysts. Also, both the Ni/CeZr(N) and NiRh/CeZr(N) catalysts displayed better durability among these catalysts over 100 h and 400 h, respectively. Since the serious coke formation for the NiCo/CeZr(N) catalyst, the activity only maintained around 6 h, the durability on the NiFe/CeZr(N) catalyst approached 50 h.