Ni–Cu–Zn/MCM-22 catalysts for simultaneous production of hydrogen and multiwall carbon nanotubes via thermo-catalytic decomposition of methane

Pure hydrogen and carbon nanotubes were produced via thermo-catalytic decomposition (TCD) of methane over Ni-loaded MCM-22 catalysts in a vertical fixed-bed reactor. The effect of reaction temperature, gas hourly space velocity (GHSV), Cu/Zn promoter and time on stream on the methane conversion, hydrogen and carbon yields were studied over the synthesized catalysts. The catalytic performance of the 50%Ni–5%Cu–5%Zn/MCM-22 catalyst was found to be highly stable compared to other catalysts. The highest conversion of methane over 50%Ni–5%Cu–5%Zn/MCM-22 catalyst reached 85% with 947% carbon yield. Methane conversion increased on increasing the reaction temperature up to 750 °C and decreased thereafter at higher temperatures. XRD and TEM analysis of the carbon byproduct revealed that graphitic carbon appeared as a major crystalline phase during the reaction. HRTEM results revealed that most of the Ni particles were located on the tip of the carbon nanofibers/nanotubes formed on the spent catalysts. The carbon nanofibres have an average outer diameter of approximately 20–40 nm with an average length of 450–500 nm. Four types of carbon nanofibers were detected and their formation strongly depended on the reaction temperature, time on stream and degree of the interaction between the metallic Ni particle and support. The optimum conditions for CNT production within the experimental ranges were found at a reaction temperature of 750 °C.     

Various nickel doping in commercial Ni–Mo/Al2O3 as catalysts for natural gas decomposition to COx-free hydrogen production

Non-oxidative decomposition of natural gas to CO_x-free hydrogen production over commercial nickel-molybdate hydrotreating catalysts with different Ni loading from 5 to 40wt% were studied at 700 °C. The catalysts were characterized by XRD, BET, TEM, Raman spectroscopy and TG-DTA analysis. The catalytic decomposition activities showed that a tremendous hydrogen production (∼90%) was obtained over 20–40wt%Ni/Mo–Al₂O₃ catalysts. Moreover, all catalysts exhibited excellent durability up to 9 h with stable catalytic activity toward H₂ production. Although the increase of Ni content reduces the catalyst surface area, the H₂ productivity and longevity increases with increased Ni content, i.e., the catalytic decomposition activity primarily depends on the active Ni sites which overcompensates the surface deficiencies. TEM, TGA and XRD data of used catalysts indicated that a higher thermal stability and graphitization degree of multi-walled carbon nanotubes were obtained on all Ni containing catalysts. Higher metal loading produced carbon nanofibers beside CNTs due to increment of particle size and long reaction time.     

Nanocomposite Ni/ZrO2: Highly active and stable catalyst for H2 production via cyclic stepwise methane reforming reactions

This work investigates the catalytic performance of nanocomposite Ni/ZrO₂-AN catalyst consisting of comparably sized Ni (10–15 nm) and ZrO₂ (15–25 nm) particles for hydrogen production from the cyclic stepwise methane reforming reaction with either steam (H₂O) or CO₂ at 500–650 °C, in comparison with a conventional Ni/ZrO₂-CP catalyst featuring Ni particles supported by large and widely sized ZrO₂ particles (20–400 nm). Though both catalysts exhibited similar activity and stability during the reactions at 500 and 550 °C, they showed remarkably different catalytic stabilities at higher temperatures. The Ni/ZrO₂-CP catalyst featured a significant deactivation even during the methane decomposition step in the first cycle of the reactions at ≥600 °C, but the Ni/ZrO₂-AN catalyst showed a very stable activity during at least 17 consecutive cycles in the cyclic reaction with steam. Changes in the catalyst beds at varying stages of the reactions were characterized with TEM, XRD and TPO–DTG and were correlated with the amount and nature of the carbon deposits. The Ni particles in Ni/ZrO₂-AN became stabilized at the sizes of around 20 nm but those in Ni/ZrO₂-CP kept on growing in the methane decomposition steps of the cyclic reaction. The small and narrowly sized Ni particles in the nanocomposite Ni/ZrO₂-AN catalyst led to a selective formation of filamentous carbons whereas the larger Ni particles in the Ni/ZrO₂-CP catalyst a preferred formation of graphitic encapsulating carbons. The filamentous carbons were favorably volatilized in the steam treatment step but the CO₂ treatment selectively volatilized the encapsulating carbons. These results identify that the nature but not the amount of carbon deposits is the key to the stability of Ni/ZrO₂ catalyst and that the nanocomposite Ni/ZrO₂-AN would be a promising catalyst for hydrogen production via cyclic stepwise methane reforming reactions.     

Hydrogen production via methane decomposition on Raney-type catalysts

The catalytic decomposition of methane into hydrogen and carbon was studied on La₂O₃ doped Ni and Ni–Cu Raney-type catalysts. The activity and stability of the catalysts were assessed by comparing the experimental conversions with the calculated equilibrium conversions for each set of experimental conditions, and the maximum conversions with the conversions at the end of (at least) 5 h tests, respectively. Improved stability of La₂O₃ doped catalysts was ascribed to an electronic promotion effect. There is an optimum load of the promoter, which provides for extended periods of stable catalyst operation. The carbon deposits consist of carbon nanofibers and multiwall carbon nanotubes. The La₂O₃ doped Ni–Cu Raney-type catalysts presented in this work are remarkably efficient for the production of hydrogen by methane decomposition.     

Synthesis gas production in the combined CO2 reforming with partial oxidation of methane over Ce-promoted Ni/SiO2 catalysts

A series of nickel-based catalyst supported on silica (Ni/SiO₂) with different loading of Ce/Ni (molar ratio ranging from 0.17 to 0.84) were prepared using conventional co-impregnation method and were applied to synthesis gas production in the combination of CO₂ reforming with partial oxidation of methane. Among the cerium-containing catalysts, the cerium-rich ones exhibited the higher activity and stability than the cerium-low ones. The temperature-programmed reduction (TPR) and UV–vis diffuse reflectance spectroscopy (UV–vis DRS) analysis revealed that the addition of CeO₂ reduced the chemical interaction between Ni and support, resulting in an increase in reducibility and dispersion of Ni. Over NiCe-x/SiO₂ (x = 0.17, 0.50, 0.67, 0.84) catalysts, the reduction peak in TPR profiles shifted to the higher temperature with increasing Ce/Ni molar ratio, which was attributed to the smaller metallic nickel size of the reduced catalysts. The transmission electron microscopy (TEM) and X-ray diffraction (XRD) for the post-reaction catalysts confirmed that the promoter retained the metallic nickel species and prevented the metal particle growth at high reaction temperature. The NiCe-0.84/SiO₂ catalyst with small Ni particle size exhibited the stable activity with the constant H₂/CO molar ratio of 1.2 during 6-h reaction in the combination of CO₂ reforming with partial oxidation of methane at 850 °C and atmospheric pressure.     

Effect of CaO–ZrO2 addition to Ni supported on γ-Al2O3 by sequential impregnation in steam methane reforming

Ni catalysts supported on (CaO–ZrO₂)-modified γ-Al₂O₃ were prepared by sequential impregnation. The effects of varied CaO to ZrO₂ mole ratios at 0, 0.20, 0.35, 0.45, and 0.55 on the activity and stability of the modified Ni catalysts were studied. As a result of using CaO–ZrO₂ as a promoter, each catalyst contained CaO–ZrO₂ at only 5%. γ-Al₂O₃ used as support was modified by CaO–ZrO₂ before the deposition of nickel oxide. The addition of CaO–ZrO₂ at an optimum ratio was expected to improve the stability of Ni catalysts due to the decrease of carbon formation resulting from carbon gasification. All the fresh catalysts were characterized by ICP, XRD, BET surface area, TGA in H₂, and TPR before catalytic testing in steam methane reforming at 600 °C. The spent catalysts were examined by TEM and TGA to observe the catalysts deactivation. The identification of CaO–ZrO₂ phases indicated that CaO and ZrO₂ reacted with each other to be monoclinic solid solution ZrO₂, CaZr₄O₉, CaZrO₃, and CaO corresponding to the phase diagram of CaO–ZrO₂. The existence of CaZrO₃ for 0.55 mol ratio of CaO/ZrO₂ enhanced activity in steam methane reforming because oxygen vacancies in CaZrO₃ greatly preferred the water adsorption creating the favorable conditions for carbon gasification and, then, water gas shift. The prominence and continued existence of these two reactions on the Ni catalysts leads to the particular increase of H₂ yield. Moreover, the increasing amount of CaZrO₃ in the Ni catalysts significantly improved carbon gasification. However, the Ni catalysts with CaZrO₃ showed whisker carbon after catalytic testing; this carbon specie has not been tolerated in steam methane reforming. Therefore, these results significantly differed from the hypothesis.     

Production of high purity hydrogen by sorption enhanced steam reforming of crude glycerol

Here we report effective production of pure hydrogen from crude glycerol by the one-stage sorption enhanced steam reforming (SESR) process. This process yielded H₂ up to 88% with a very high purity (99.7 vol%) at atmospheric pressure and at 550–600 °C with a steam/C = 3 in a fixed-bed reactor over a mixture of Ni/Co catalyst derived from hydrotalcite-like material (HT) and dolomite as CO₂ sorbent. The concentration of methane is lowest at 575 °C, while the CO concentration increases concurrently with increasing temperature from 525 to 600 °C. The high coking potential of glycerol and fatty acid methyl esters (C₁₇–C₁₉) resulted in the increased formation of coke, thus lower hydrogen yield. The reaction rates of methane reforming and water–gas shift reactions are much higher than the steam reforming of crude glycerol on Co–Ni catalysts. The high purity of hydrogen can be obtained even at low spatial times with low crude glycerol conversions. Our work reveals a great potential to directly convert biomass derived complex mixtures to the most clean energy carrier of hydrogen with high yield and purity.     

Influence of alloying on the catalytic performance of Ni–Al catalyst prepared from hydrotalcite-like compounds for methane decomposition

Cobalt-, iron-, and copper-substituted nickel-aluminum hydrotalcite-like compounds (Ni_2.7Co_0.3Al, Ni_2.7Fe_0.3Al, Ni_2.7Cu_0.3Al HTlcs) have been synthesized and used as precursors to prepare Ni–Co, Ni–Fe, and Ni–Cu alloy catalysts for methane decomposition. The catalysts before and after reaction were characterized with various techniques including XRD, H₂-TPR, HAADF-STEM-EDX, SEM, TEM, and Raman. The characterization results indicate that upon calcination HTlcs are transformed into a mixed oxide solid solution, where cobalt, copper, and iron ions are incorporated into the nickel oxide, and the reduction treatment leads to composition-uniform alloy particles. In methane decomposition at 600 °C, alloying Ni with Co, Fe, and especially Cu is found to enhance the catalytic life and carbon yield. The order of activity is Ni_2.7Cu_0.3Al >> Ni_2.7Fe_0.3Al > Ni_2.7Co_0.3Al > Ni₃Al in terms of carbon yield, highlighting that Ni–Cu alloying is the most effective. Besides, Ni–Cu alloying remarkably changes the carbon morphology, giving carbon nanofibers as the main product. TEM and STEM measurements suggest that Ni–Cu alloy particles are readily aggregated into big particles (>60 nm) under the reaction conditions, which may be responsible for the significant effect of Ni–Cu alloying.     

Water effect in hydrogen production from methane

Ni/MgO and Ni/Al₂O₃ catalysts were prepared, by wet impregnation, to compare their performance in hydrogen production from methane CPO, wet-CPO and SR. The catalytic activity was tested at 1073 K, 1 bar and 600–1200 h⁻¹. Fresh and used catalysts were characterized by different techniques. Both supports, as expected, had a low surface area (27.1 m²/g MgO and 6.2 m²/g α-Al₂O₃), as determined by BET method. The images obtained with SEM and TEM revealed that the Ni was more dispersed in the MgO support than in the Al₂O₃ one. By XRD a strong interaction, as solid-solution, between NiO and MgO was found in the 30Ni/MgO and 40Ni/MgO catalysts. The fresh 40Ni/Al₂O₃ reduced catalyst was partially reduced. But after the activity tests the stability of the reduced Ni became bigger. Some Ni sintering was also observed in the 40Ni/Al₂O₃ after the wet-CPO and SR tests. The behaviour of the three catalysts was very good in CPO methane conversion (90–93%), but the gradual increase of the steam to carbon ratio, wet-CPO and SR, affected negatively the conversion.     

Characterization and activity test of commercial Ni/Al2O3, Cu/ZnO/Al2O3 and prepared Ni–Cu/Al2O3 catalysts for hydrogen production from methane and methanol fuels

In this study, methane and methanol steam reforming reactions over commercial Ni/Al₂O₃, commercial Cu/ZnO/Al₂O₃ and prepared Ni–Cu/Al₂O₃ catalysts were investigated. Methane and methanol steam reforming reactions catalysts were characterized using various techniques. The results of characterization showed that Cu particles increase the active particle size of Ni (19.3 nm) in Ni–Cu/Al₂O₃ catalyst with respect to the commercial Ni/Al₂O₃ (17.9). On the other hand, Ni improves Cu dispersion in the same catalyst (1.74%) in comparison with commercial Cu/ZnO/Al₂O₃ (0.21%). A comprehensive comparison between these two fuels is established in terms of reaction conditions, fuel conversion, H₂ selectivity, CO₂ and CO selectivity. The prepared catalyst showed low selectivity for CO in both fuels and it was more selective to H₂, with H₂ selectivities of 99% in methane and 89% in methanol reforming reactions. A significant objective is to develop catalysts which can operate at lower temperatures and resist deactivation. Methanol steam reforming is carried out at a much lower temperature than methane steam reforming in prepared and commercial catalyst (275–325 °C). However, methane steam reforming can be carried out at a relatively low temperature on Ni–Cu catalyst (600–650 °C) and at higher temperature in commercial methane reforming catalyst (700–800 °C). Commercial Ni/Al₂O₃ catalyst resulted in high coke formation (28.3% loss in mass) compared to prepared Ni–Cu/Al₂O₃ (8.9%) and commercial Cu/ZnO/Al₂O₃ catalysts (3.5%).     

Catalytic activity and characterizations of Ni/K2TixOy–Al2O3 catalyst for steam methane reforming

Nickel catalysts supported on the K₂Ti_xO_y–Al₂O₃ were prepared by the wet impregnation method for steam methane reforming to produce hydrogen. X-ray diffraction, N₂ physisorption, scanning electron microscopy with energy dispersive spectroscopy, the H₂ temperature-programed reduction technique, and X-ray photoelectron spectroscopy were employed for the characterization of catalyst samples. The results revealed that the performance of the Ni/K₂Ti_xO_y–Al₂O₃ catalysts was comparable to that of commercial FCR-4 for steam methane reforming under the mild condition. In particular, a catalytic stability test at 800 °C and in the reactant flow with the steam-to-carbon (S/C) feed ratio of 1.0 indicated that the Ni/K₂Ti_xO_y–Al₂O₃ catalysts were more active, thermally stable and resistant to deactivation than the non-promoted Ni/Al₂O₃. It is considered that the appropriate interaction strength between nickel and the modified support and proper K₂Ti_xO_y phases with a surface monolayer coverage achieved at ca. 15 wt.% loading in the support play important roles in promoting the steam methane reforming activity as well as suppressing the sintering of the catalyst.     

The effect of different atmosphere treatments on the performance of Ni/Nb–Al2O3 catalysts for methane steam reforming

Methane steam reforming is currently the most widely used hydrogen production reaction in industry today. Ni/Nb–Al₂O₃ catalysts were prepared by treatment under H₂, N_2, and air atmosphere prior to reduction and applied for methane steam reforming reaction at low temperature (400–600 °C). The hydrogen-treated catalysts increased catalytic activity, with 55.74% methane conversion at S/C = 2, GSVH of 14400 mL g^?1 h^?1 and 550 °C. The H₂ atmosphere treatment enhanced the Ni–Nb interaction and the formation of stable, tiny, homogeneous Ni particles (6 nm), contributing to good activity and stability. In contrast, the catalysts treated with nitrogen and air showed weaker interactions between Ni and Nb species, whereas the added Nb covered the active sites, which caused the decrease in activity. Meanwhile, carbon accumulation was also observed. This work is informative for preserving small nano-sized nickel particles to enhance catalytic performance.     

Characterization and catalytic behavior of hydrotalcite-derived Ni–Al catalysts for methane decomposition

A series of Ni catalysts were prepared from Ni–Al hydrotalcite-like compounds (HTlcs) by varying the Ni/Al molar ratio (1–4) and calcination temperature (773–1173 K) of HTlcs. The catalysts were reduced with H₂ at 1073 K and tested for CH₄ decomposition at 773–923 K on a thermal gravimeter. Various techniques including N₂ physical adsorption, XRD, H₂-TPR, XPS, HAADF-STEM, TEM, and Raman were applied to characterize the catalysts and the as-produced carbon. The characterizations show that calcination of Ni–Al HTlcs leads to Ni(Al)O solid solution and minor NiO and/or NiAl₂O₄ spinel may be formed depending on the Ni/Al ratio and calcination temperature; upon reduction at 1073 K, most nickel species are reduced to metallic Ni. In CH₄ decomposition, carbon yield shows a volcano-type dependence on the Ni content with the optimum Ni/Al ratio equal to 3. On the other hand, carbon yield is affected by the calcination temperature of the Ni₃Al HTlcs to a small extent. Carbon yield is also significantly affected by the reaction temperature, which decreases remarkably with a rise of temperature to 923 K. TEM and Raman indicate that fish-bone carbon nanofibers are formed at 773–823 K, whereas multi-walled carbon nanotubes are formed at 873–923 K.     

Pore diameters of Ni/ZrO2 catalysts affect properties of the coke in steam reforming of acetic acid

Pore structures of support affect not only the dispersion of metals species, but also the catalytic stabilities and the properties of the generated coke in steam reforming reaction of acetic acid. This has been demonstrated in this study with Ni/ZrO₂ catalysts of varied pore diameters. The results showed that the Ni/ZrO₂ catalyst with the support calcined at 700 °C had the largest diameter, which facilitated the entering of nickel species into the pores, suppressing the migration and agglomerate in reduction of the catalysts. Although the catalysts with the varied pore diameters showed little impacts on the catalytic performances, the properties of the coke varied substantially. The catalyst with the large pore diameter favored the growth of the crystal carbon in the coke to a bigger size and was more tolerant to coke accumulation while maintained the catalytic stability. In addition, thermal stability, resistivity to oxidation, aromaticity, functionalities and the morphologies of the coke (i.e. carbon nanofibers, carbon nanotubes and bamboo-like structure) were all connected with the porous structures of the Ni/ZrO₂ catalysts.     

Ethanol steam reforming for hydrogen generation over structured catalysts

The present paper reports on the preparation, characterization and reaction evaluation of structured catalysts toward hydrogen generation via ethanol steam reforming. To these ends, 400 cpsi cordierite monoliths were functionalized with Rh–Pd/CeO₂ catalyst. SEM, TEM and XRD showed a uniform and well-covering CeO₂ layer where Rh–Pd nanoparticles of less than 0.5 nm were anchored. The functionalized monoliths were successfully tested for synthesis gas production from ethanol steam reforming. Realistic operating conditions were selected, including temperatures between 500 and 950 K, pressures from 1 to 6 bar, undiluted ethanol:water molar ratios 1:4–1:8 (i.e., 2 ≤ S/C ≤ 4) and a wide range of feed loads. Appropriate activity and hydrogen selectivity were verified for the catalytic system, with ca. complete ethanol conversion at T > 700 K and a minor, or even negligible, generation of by-products (acetaldehyde, acetone, ethane, ethylene). Operating at 950 K and 1.5 bar, a H₂ yield of 3.4 mol hydrogen per mol ethanol in feed was achieved for a liquid feed load of 0.22 μl_liq/(mg_cat min) (S/C = 3), with 8.1% of CH₄ and 8.2% of CO on dry basis. Kinetic parameters of a phenomenological set of reaction rate equations were fitted against experimental data, considering ethanol decomposition (methane formation) with subsequent methane steam reforming to both CO and CO₂ and water–gas shift reaction.     

Preparation of highly stable bimetallic Ni–Cu catalyst for simultaneous production of hydrogen and fish-bone carbon nanofibers: Optimization,effect of catalyst preparation methods and deactivation

This paper presents the preparation of highly stable nano-porous Ni–Cu catalysts for simultaneous production of CO_x–free hydrogen and carbon nano-fibers. The main features of this work focuses on the optimization, methods of catalyst preparation and application of an experimental model for deactivation. The fresh catalysts and the deposited carbon were characterized by SEM, TEM, XRD and Raman spectroscopy. Whatever to be the preparation methods, performance tests showed that the presence of Cu as promoter in Ni–Cu–MgO catalysts, enhanced the catalytic activity, substantially at higher temperatures with the best result obtained for Ni–Cu–MgO catalyst prepared by one step sol- gel method, reaching a hydrogen concentration of 70 vol% (160.51 mol H₂/mol Ni-1 h) and a smaller value of I_D/I_G (less imperfection) for produced carbon nano-fibers at 670 °C. Detailed rate-based model for deactivation of catalyst was found to be dependent on the time, reaction temperature and partial pressure of methane and indicated that the reaction of deactivation could be modeled by a simple hyperbolic model.     

Evaluation of Ni/Y2O3/Al2O3 catalysts for hydrogen production by autothermal reforming of methane

Ni/xY₂O₃–Al₂O₃ (x = 5, 10, 15, 20 wt%) catalysts were prepared by sequential impregnation synthesis. The catalytic performance for the autothermal reforming of methane was evaluated and compared with Ni/γ-Al₂O₃ catalyst. The physicochemical properties of catalysts were characterized by X-ray diffraction (XRD), Transmission electron microscope (TEM), X-Ray Photoelectron Spectrometer (XPS), Thermo Gravimetric Analyzer (TGA) and H₂-temperature programmed reduction techniques (TPR). The decrease of nickel particle size and the change of reducibility were found with Y modification. The CH₄ conversion increased with elevating levels of Y₂O₃ from 5% to 10%, then decreased with Y content from 10% to 20%. Ni/xY₂O₃–Al₂O₃ catalysts maintained high activity after 24 h on stream, while Ni/Al₂O₃ had a significant deactivation. The characterization of spent catalysts indicated that the addition of Y retarded Ni sintering and decreased the amount of coke.     

Low metal content Co and Ni alumina supported catalysts for the CO2 reforming of methane

Low metal content Co and Ni alumina supported catalysts (4.0, 2.5 and 1.0 wt% nominal metal content) have been prepared, characterized (by ICP-OES, TEM, TPR-H₂ and TPO) and tested for the CO₂ reforming of methane. The objective is to optimize the metal loading in order to have a more efficient system. The selected reaction temperature is 973 K, although some tests at higher reaction temperature have been also performed. The results show that the amount of deposited carbon is noticeably lower than that obtained with the Co and Ni reference catalysts (9 wt%), but the CH₄ and CO₂ conversions are also lower. Among the catalysts tested, the Co(1) catalyst (the value in brackets corresponds to the nominal wt% loading) is deactivated during the first minutes of reaction because CoAl₂O₄ is formed, while Ni(1) and Co(2.5) catalysts show a high specific activity for methane conversion, a high stability and a very low carbon deposition.     

Glycerol steam reforming on supported Ru-based catalysts for hydrogen production for fuel cells

Glycerol steam reforming on Ru and Ru–Me (Me = Fe, Co, Ni, and Mo) catalysts supported on yttria, ceria–zirconia, and γ-alumina is studied at high temperatures for the production of hydrogen for fuel cell applications. The nature of the support notably affects the catalytic properties of these catalysts resulting in significant enhancements of the H₂ production turnover rate and product selectivity on the reducible yttria and ceria–zirconia supported Ru-based catalysts via facilitation of the water–gas shift reaction. The acidic γ-alumina supported Ru-based catalysts demonstrate a low H₂ production turnover rate with a high CO product selectivity and also favor the formation of C₁–C₂ hydrocarbons. Differently, the promotion effects due to Fe, Co, Ni, and Mo on the bimetallic Ru–Me catalysts are limited with only small increases in the glycerol conversion turnover rate for the Ru–Ni, Ru–Mo, and Ru–Co catalysts. The alumina supported Ru-based catalysts are deactivated by a significant extent with increasing on-stream time due to coking. The carbon deposition is insignificant on the yttria and ceria-zirconia supported catalysts, but moderate deactivation occurs due to sintering of the dispersed metal clusters. Influenced by the surface MoO_x species that hamper sintering of the surface metal clusters and by the Y₂O₃ support that prevents coking on the catalyst, the Ru–Mo/Y₂O₃ catalysts exhibit superior catalytic stability against deactivation.     

Inhibition of carbon formation during steam reforming of methane using thiol-coated nickel catalysts

n-Butanethiol-impregnated, micrometric, pristine Ni powder (Ni–C₄S) was tested as a catalyst for use in the steam reforming of methane, using X-Ray photoemission spectroscopy (XPS) and mass spectrometry (MS). The catalytic activities of both the pristine Ni and the Ni–C₄S powders were measured at 700 °C, under conditions that favoured (molar CH₄:H₂O ratio of 2:1), and did not favour (molar CH₄:H₂O ratio of 1:2) formation of surface carbon. The results show that: (a) Ni–C₄S demonstrates both high catalytic activity and stability during the 21 h duration test; (b) under conditions favouring the deposition of surface carbon, the Ni–C₄S retained both its efficiency and structural integrity, while the catalytic activity of the Ni was reduced by ∼70% and the catalyst pellets lost their integrity; (c) the amount of deposited carbon in the case of the Ni–C₄S catalyst was significantly lower than that observed for the Ni catalyst, in spite of the longer testing duration. It was concluded that the thiols pre-treatment of Ni surfaces, to be subsequently used in the production of catalysts supported SOFC anodes, can considerably increase their “active life span” this being a critical attribute in respect of their eventual commercialization.