Reforming Of Toluene Research Articles

Roles of alkali/alkaline earth metals in steam reforming of biomass tar for hydrogen production over perovskite supported Ni catalysts

Biomass steam gasification has a large potential to produce high-purity hydrogen, and perovskites are good candidates to act as catalyst supports in eliminating the biomass tar produced during reforming. However, various alkali and alkaline earth metals are contained in actual biomass, which would be released during reactions and could affect the catalytic performance of perovskite-supported catalysts. To explore potential roles of alkali and alkaline earth metals in the catalysis process, in this work, typical K, Ca and Mg were added into Ni/La0.7Sr0.3AlO3−x catalysts, and their performance in steam reforming of toluene as a model of biomass tar for hydrogen production were investigated comprehensively. Catalytic performance shows that the presence of K, Ca, and Mg leads to a better resistance to coking (a reduction of over 60%) and sintering of the Ni/perovskite catalysts utilized, and this trend becomes more pronounced as the decrease of reaction temperature. Furthermore, a series of catalyst characterizations, including XRF, XRD, SEM, TPR, TPD, and XPS were conducted to understand the action mechanism. And results reveal that the presence of K, Ca, and Mg in catalysts promotes the absorption ability of surface oxygen, which could oxidize reaction intermediates or the carbon deposited, thus enabling good reforming properties of the perovskite-supported Ni catalysts in the reforming of biomass tar.

Catalytic Steam Reforming of Toluene for Hydrogen Production over Nickel-Cobalt Supported Activated Carbon

Hydrogen may play a key role in future sustainable energy system as a carrier of renewable energy to replace the conventional fossil fuel. Biomass gasification is the most promising method in renewable hydrogen production technologies. However, the tar by-product poses great obstacle in the realization of commercial biomass gasification. In this work, the performance of Ni and/or Co supported on modified-palm kernel shell-derived activated carbon (AC) catalyst in steam reforming of toluene (SRT) for the production of hydrogen has been investigated. Toluene has been chosen as a model compound since it represents one of the major tar compositions. The effects of nitric acid in the surface pretreatment of AC (ACN) and the influence of Ni and/or Co loading on the catalyst support are studied. The catalysts are characterized using FTIR, BET, XRD, TGA and FESEM-EDX. The modified-AC support shows that the surface area, microporous structure and surface oxygenated functional group (SOFG) increase, leading to a homogeneous distribution of metal particles. The highest toluene conversion (Xtoluene) and hydrogen yield (YH2) obtained over 10%Ni-10%Co/ACN are 70% and 69%, respectively. The catalytic performance of bimetallic Ni–Co/ACN catalyst is more significant compared to monometallic Ni- and Co-supported catalysts. The highest catalytic performance achieved can be attributed to the larger surface area and unique porous structure of the modified-AC support as well as the formation of Ni–Co solid solution alloys that improve its coke-resistant capability with low carbon formation during SRT. The modified palm kernel shell AC-supported bimetal catalyst has high potential as a biomass-based catalyst for the applications in biomass tar removal toward hydrogen production due to its good coke-resistance properties.

Plasma reforming of toluene as a model tar compound from biomass gasification: effect of CO2 and steam

In this study, plasma reforming of toluene as a tar model compound from biomass gasification has been carried out using an AC gliding arc discharge reactor. The influence of steam and CO2 addition on the reforming of toluene has been evaluated. The results show that the highest toluene conversion (59.9%) was achieved when adding 3 vol% CO2 at a toluene concentration of 16.1 g/Nm3 and a specific energy input of 0.25 kWh/m3. Further increasing CO2 concentration to 12 vol% decreased the conversion of toluene. The presence of steam in the plasma CO2 reforming of toluene creates oxidative OH radicals which contribute to the enhanced conversion of toluene and energy efficiency of the plasma reforming process through stepwise oxidation of toluene and reaction intermediates. Hydrogen and C2H2 were identified as the major gas products in the plasma reforming of toluene without CO2 or steam, with a yield of 9.7% and 14.5%, respectively, while syngas was the primary products with a maximum yield of 58.3% (27.5% for H2 and 30.8% for CO) in the plasma reforming with the addition of 12 vol% CO2. The plausible reaction pathways and mechanism in the plasma reforming of toluene have been proposed through the combination of the analysis of gas and condensed products and spectroscopic diagnostics.

Study on catalytic cracking of toluene as the model compound of tar by different catalysts

AbstractIn this work, three catalysts (Ni‐based catalyst, Ni/Fe‐based catalyst, and Ni/Ce‐based catalyst) were developed for catalytic cracking of toluene as a model compound of tar in a fixed bed reactor. The characteristic of catalysts were determined by XRD, EDX, and BET. Meanwhile, the effects of calcination temperature and reaction temperature on syngas yield and toluene conversion rate were also studied. The results showed that the BET surface area was decreased with the rise of calcination temperature, while the content of hydrogen and syngas yield were decreased with the rise of calcination temperature. The three catalysts showed a promising application in catalytic reforming of toluene for hydrogen production. The catalytic performance of three catalysts was ordered as Ni/Ce > Ni/Fe > Ni > thermal cracking. The maximum syngas yield (1.44 L/g toluene) and toluene conversion rate (96.4%) were obtained for Ni/Ce‐based catalyst, which indicated the effectiveness of the Ni/Ce‐based catalyst.

Hydrogen production through steam reforming of toluene over Ce, Zr or Fe promoted Ni-Mg-Al hydrotalcite-derived catalysts at low temperature

Ni-Mg-Al hydrotalcite-derived materials promoted with Ce, Zr or Fe were prepared by the co-precipitation method, which exhibited excellent performance in steam reforming of toluene (SRT) at low temperature. Especially, Fe-doped catalyst had higher catalytic activity and stability at 400 °C, which maintained almost 100% toluene conversion during the SRT reaction (3 h). Moreover, it also had higher hydrogen production and better selectivity for hydrogen production. The physico-chemical characterizations and model simulation indicate its high dispersion of active sites and accessibility of reactants to active sites: uniform dispersion of active sites (SEM, TEM and EDX), large specific surface area (151 m2/g), pore volume (0.84 cm3/g) and average pore diameter (22.1 nm), small crystallite size (34.9 nm), desirable Ni species reducibility (TPR), high basicity (TPD), low metal carbide formation (XPS), and good adsorption affinity with toluene (−18.391 kJ mol−1, DFT). Moreover, less carbon was deposited on the Fe-containing catalyst through measuring the amorphous carbon and CNTs by the TG-MS method, which was due to the tip-growth mechanism of CNTs. Considering lower toluene conversion temperature, higher hydrogen yield, and better resistance to carbon deposition, this study may be meaningful in development of SRT at low temperature.

Ni-doped γ-Al2O3 as secondary catalyst for bio-syngas purification: influence of Ni loading, catalyst preparation, and gas composition on catalytic activity

In this work, Ni/γ-Al2O3 catalysts were prepared by sol-gel methods with different Ni loadings (10–50 wt.%) and used as secondary catalyst for the steam reforming of toluene. A sample prepared by wet impregnation with 10 wt.% of Ni was also synthesized and compared with the corresponding sol-gel sample. This study was divided in three main parts: the comparison of catalysts prepared by sol-gel process and impregnation, the influence of the gas composition on the catalytic performance of the sol-gel 10 wt.% Ni/γ-Al2O3 catalyst, and the influence of Ni loading on the catalytic activity. When sol-gel and impregnated samples are compared, the impregnated catalyst showed a high initial toluene conversion followed by a consequent and progressive deactivation. Contrarily, the sol-gel catalyst showed a stable catalytic activity and relatively low carbon deposit. Indeed, before the steam reforming of toluene at 650 °C, the sol-gel catalyst was only calcined and no reduction step was realized to reduce nickel oxide. So this sample was reduced during the catalytic test at 650 °C. Moreover, it was observed that if toluene was withdrawn from the syngas mixture during the catalytic test, the sol-gel sample was progressively reoxidized by CO2 and H2O, leading to higher deactivation. As the Ni loading increased, the nickel oxide with strong interactions (NiAl2O4) was progressively joined by nickel oxide with low interactions (NiO/Al2O3) and bulk nickel oxide (NiO). This led to a high initial conversion of toluene but also to a progressive loss of the catalytic activity throughout the catalytic test. It was shown that the sol-gel method developed throughout this work allowed preparing microporous/mesoporous Ni/γ-Al2O3 catalysts with a high dispersion of Ni nanoparticles.

Enhanced reforming of mixed biomass tar model compounds using a hybrid gliding arc plasma catalytic process

Abstract Plasma-catalytic steam reforming of mixed tar model compounds (toluene and naphthalene) from biomass gasification has been carried out in a gliding arc discharge (GAD) plasma reactor. The influence of three catalysts (15Ni, 7.5Ni7.5Co and 15Co) on the performance of the plasma reforming of toluene and naphthalene has been evaluated including the conversion, the energy efficiency, the yield/selectivity of gaseous products and the formation of by-products. A plasma-catalysis synergy was generated when introducing the catalysts to the plasma tar reforming process. The highest toluene conversion of 95.7% and naphthalene conversion of 83.4% were achieved when the 7.5Ni7.5Co catalyst was integrated with the GAD plasma at a total tar concentration of 16.0 g/Nm3 and a discharge power of 75 W. The corresponding energy efficiency for the conversion of toluene and naphthalene was 38.0 g/kWh and 2.3 g/kWh, respectively, giving the highest total tar conversion of 95.1% and overall energy efficiency of 40.3 g/kWh. The coupling of GAD with the 7.5Ni7.5Co catalyst also showed the highest yield of H2 (42.3%) and CO (37.3%) and the highest CO selectivity of 40.1%. In addition, the combination of the GAD plasma with 7.5Ni7.5Co reduced the carbon deposition on the catalyst surfaces and the formation of by-products in the plasma-catalytic tar reforming process. The enhanced reducibility and NiCo alloy formation of the 7.5Ni7.5Co catalyst contribute to the enhanced conversion of mixed tar compounds and the formation of the plasma-catalysis synergy in the hybrid plasma-catalytic tar reforming process.

Plasma reforming of biomass gasification tars using mixed naphthalene and toluene as model compounds

Non-equilibrium plasma technology provides an unconventional but promising solution for the cleaning of tar contaminated bio-syngas in biomass gasification. This work is focused on the reforming of mixed naphthalene (C10H8) and toluene (C7H8) as typical single ring and double ring tar model components using a gliding arc discharge (GAD) reactor. The influence of naphthalene content, steam/carbon molar ratio and discharge power on the destruction of C10H8 and C7H8 was evaluated to understand their effects on the tar conversion, gas yield, and the energy consumption. Adding H2O to the plasma process forms OH radicals, creating additional reaction routes for the step-wised oxidation of naphthalene, toluene and their fragments towards the production of CO, CO2, and water. The highest conversion of naphthalene and toluene (∼80% overall) was obtained when the steam/carbon molar ratio changed between 1.0 and 1.5, which was dependent on the balance between two opposite effects due to the presence of steam: positive effect of OH radicals and negative effect of electron attachment on water molecules. The highest energy efficiency (53.6 g/kWh) was obtained for the conversion of mixed tar compounds, which is by far the highest in previously reported works. CO, H2 and C2H2 were the major gases with the highest CO yield of 38.6% and H2 yield of 39.1%. Emission spectroscopic diagnostics was employed to understand the contribution of chemically reactive species to the GAD reaction. Possible reaction pathways in the plasma reforming of mixed naphthalene and toluene were proposed based on the plasma spectroscopic diagnostics coupled with a comprehensive analysis of major gas products and condensable by-products.

Plasma-enhanced steam reforming of different model tar compounds over Ni-based fusion catalysts.

Tar formation during biomass gasification is undesirable due to the decreased energy efficiency and increased costs for maintaining downstream equipment. The hybrid non-thermal plasma-catalysis method is considered to be a promising alternative, since it overcomes the disadvantages arising from both catalyst deactivation during catalytic reforming and the formation of undesirable liquid by-products in plasma reforming. SiO2- and ZSM-5-supported Ni-based catalysts with different Ni loadings (0.5, 1, 3, and 5 wt%) were prepared by thermal fusion and applied to the steam reforming of toluene. Different characterizations of fresh and spent catalysts including XRD, H2-TPR, N2 adsorption-desorption, SEM, TEM, XPS and TGA were conducted to show the properties of catalysts. The results indicated that Ni/ZSM-5 exhibited better performance than Ni/SiO2, due to the increased dispersion of Ni particles and the stronger metal-support interaction of Ni/ZSM-5, which was confirmed by the TEM and H2-TPR results. In addition, the performances of the catalysis-only (CatO), plasma-only (PlO), and in-plasma-catalysis (IPC) systems in steam reforming of different model tar compounds including benzene, toluene, furfural, naphthalene, fluorene and pyrene were compared using Ni(5 wt%)/ZSM-5. Obvious synergistic effects between DBD plasma and Ni(5 wt%)/ZSM-5 was observed for syngas production in the IPC system.

Synthesis of Ni/γ-Al2O3SiO2 catalysts with different silicon precursors for the steam toluene reforming

Abstract This work investigated the intrinsic properties and performances of Ni/γ-Al2O3 SiO2 modified with different silicon precursors for the steam reforming of toluene in biomass gasifier exit conditions (8000 ppmv of toluene, 650 °C). Samples were synthesized by an aqueous sol-gel process in presence of aluminum nitrate, nickel nitrate and the use of either tetramethoxysilane (TMOS, Si-(OCH3)4) or tetraethoxysilane (TEOS, Si-(OC2H5)4) in order to understand the influence of the reactivity of the silicon precursor. Furthermore, the use of N-[3-(trimethoxysilyl)propyl]ethylenediamine (EDAS, (OCH3)3 Si (CH2)3 NH (CH2)2 NH2) is also investigated in order to understand the influence of a silicon precursor containing an ethylenediamine group, able to complex Ni2+ ions. By the chelation of Ni2+ ions by ethylenediamine groups during the synthesis, Ni/γ-Al2O3 SiO2 samples modified with EDAS showed higher dispersion of the metallic Ni nanoparticles and the higher resistance against the sintering of Ni particles. This was also attributed to the high microporous volume and the narrow mesoporous distribution of the support, which could also prevent the migration of the metallic Ni nanoparticles. The catalytic tests revealed that the reactivity of the silicon precursor played a major role on the conversion of toluene. For alumina supports modified with a silicon precursor with a low reactivity such as TEOS, the low integration of the Si atoms inside the bulk alumina lead to a slightly higher catalytic activity, but also to a high formation of structured carbon. The opposite effect was observed for the samples modified with a highly reactive silicon precursor, such as TMOS or EDAS, which showed a slightly lower catalytic activity, but a higher resistance against coking compared to pure Ni/γ-Al2O3 catalysts.

Steam reforming of toluene as model of tar compound over Mo catalysts derived from hydrotalcites

This study evaluated the catalytic activity of Mo catalysts derived from hydrotalcite-like compounds for steam reforming of toluene as a model compound for tar. The catalysts with 1.5, 3 and 4.5 Mo loadings (wt%), denoted as Mo1.5MgAl, Mo3MgAl and Mo4.5MgAl respectively, were prepared by coprecipitation and characterized by BET, XRD, SEM, TEM, FT-IR and UV–VIS. The results showed that toluene conversion increased with increasing molybdenum content. The hydrogen amount depended on two factors: the presence of molybdate species on the surface and the presence of aluminum cations in tetrahedral sites (Mo3MgAl), with molybdenum influence being more pronounced. The H2/CO ratio decreased at increasing temperature while, the H2/CO2 ratio increased proportionally with temperature. Mo1.5MgAl catalyst was more selective for CO2 and H2, while, Mo3MgAl and Mo4.5MgAl were more selective for CO and H2.

Optimization of Nickel-Based Catalyst Composition and Reaction Conditions for the Prevention of Carbon Deposition in Toluene Reforming

In this study, nickel-based reforming catalysts were synthesized for the reforming of toluene, a major component of thinners and widely used as an organic solvent. The reaction characteristics of these catalysts were investigated by both steam reforming and auto-thermal reforming. Reforming aromatic hydrocarbons like toluene to produce synthesis gas is difficult because carbon deposition also occurs, and the deposition of carbon lowers the activity of the catalyst and causes a pressure drop during the reaction process. In order to maintain a stable reforming process, a catalytic reaction technique capable of suppressing carbon deposition is required. Steam reforming and auto-thermal reforming of toluene were used in this study, and the temperature of the catalyst bed was remarkably reduced, due to a strong endothermic reaction during the reforming process. By using scanning electric microscopy (SEM), X-ray diffraction (XRD), and temperature-programmed oxidation analysis, it is shown that carbon deposition was markedly generated due to a catalyst bed temperature decrease. In this study, optimum conditions for catalyst composition and the reforming reaction are proposed to suppress the formation of carbon on the catalyst surface, and to remove the generated carbon from the process. In addition, ceria and zirconia were added as catalytic promoters to inhibit carbon deposition on the catalyst surface, and the carbon deposition phenomena according to the catalyst’s promoter content were investigated. The results showed that the carbon deposition inhibition function of CeO2, via its redox properties, is insignificant in steam reforming, but is notably effective in the auto-thermal reforming of toluene.

Study on Catalytic Steam Reforming of Toluene over Ni/Activated Carbon Catalysts Prepared from Adsorption Treatment of Nickel Electroplating Wastewater by Activated Carbon

The conditions (adsorption duration and pH) for removal of nickel ions from nickel electroplating wastewater by adsorbing on activated carbon were studied. Ni/AC catalysts prepared by adsorption under alkaline conditions with high removal rate of Ni(II) has been chosen for catalytic steam reforming of toluene, and its catalytic performances were evaluated compared to that of Ni/AC catalysts prepared by impregnation. Alkaline conditions facilitated the removal of Ni(II) from nickel electroplating wastewater by AC and pH=9 in especial, was a critical point above which Ni(II) could be removed efficiently. The removal rate within 20 min reached up to more than 97%. After H2 reduction, the catalytic activity of Ni/AC-Ad was observed in catalytic steam reforming of toluene and then gradually decreased with the reaction time. Both the toluene conversion and hydrogen production with Ni/AC-Ad were about 65% of those with Ni/AC-Im at similar Ni loading rate. Under alkaline conditions, most of the nickel adsorbed on AC was Ni(OH)2 complex. This adsorption state led to a larger average size of nickel particle in Ni/AC-Ad than that in Ni/AC-Im. The uneven size of nickel particles on the surface caused poor dispersion of active spots, agglomeration and sintering, resulting in gradual deactivation of Ni/AC-Ad prepared under alkaline conditions during catalytic steam reforming of toluene.

Plasma-Aided Reforming of Toluene and Isopropanol with Analysis of Decomposition Mechanism

This paper presents experimental methods, conditions and results of plasma-aided reforming of isopropanol and toluene in water steam atmosphere. The liquid feedstock is added to nitrogen gas by a syringe pump and fed into a drop tube reactor, passing through a fluctuating non-thermal plasma zone. A comparison between plasma and thermal reforming is conducted at similar test conditions, achieving similar gas temperatures in the reactor. In the plasma case, an energy input of about 1 kW is introduced into the reaction through a gliding arc, non-thermal plasma, while in the thermal case the energy is thermally fed through a steam superheater. The measured syngas production shows a significant plasma enhancement on individual syngas components (e.g. H2, CO, CH4) using toluene. Furthermore, the reaction degree is calculated from the syngas-based carbon and hydrogen balance. Using isopropanol as feedstock, plasma increases the syngas-based carbon conversion from 35.5 to 50.2% and the hydrogen release from 47.3 to 70.1%. In the case of aromatic feedstock such as toluene, a carbon conversion from 1.2 to 9.2% and a rise of the hydrogen release from 2.1 to 29.8% is achieved. Based on hydrogen release, the reaction kinetics obtained through data-fitting in a first-order Arrhenius diagram, are accelerated from 0.43 to 0.81 s−1 and from 0.01 to 0.24 s−1 for plasma-assisted isopropanol and toluene reforming, respectively. An analysis of condensate from syngas shows that the decomposition products of toluene reforming include benzene, indene, naphthalene etc.

Evaluation of regenerative function and activity of reforming toluene by composite catalyst containing spinel oxide

Catalysts that can maintain the activity for a long time are indispensable for the distributed power generation consisting of biomass gasifier and Solid Oxide Fuel Cell (SOFC). This study aims to reveal and develop the regenerative function of composite catalysts containing NiAl2O4 that can be regenerated by reduction and oxidation (Red-Ox) for converting tar from biomass. Regenerative function of composite oxide catalyst containing NiAl2O4 spinel (NAO) and Ru added to NAO (RNAO) by Red-Ox cycles and their activity of autothermal reforming of toluene were examined. Regenerating function of NAO and RNAO were investigated by temperature programmed reduction (TPR) and oxidation at 850 °C repeatedly. After 7th times Red-Ox cycles at 850 °C, though the regenerated amount of Ni in NAO decreased by 70%, that in RNAO was maintained. By Red-Ox of NAO and RNAO, Ni was oxidized to NiO at 350–650 °C and dissolved into γ-Al2O3 to form the NiAl2O4 spinel at above 750 °C. In RNAO, RuO2 particles were more dispersed, decreasing its particle size than the initial, with the Red-Ox cycles, since Ru was dissolved into the Ni particles exsoluted from NiAl2O4. By evaluating the activity of autothermal reforming of toluene, NAO and RNAO showed 1.5–3.0 times higher activity than Pt/γ-Al2O3, due to the highly dispersive active sites unoccupied by CO. Since the active metals can be redispersed by oxidation and reduction at the range from 750 °C to 850 °C, NAO and RNAO would contribute the maintenance free system for reforming tar from biomass gasification.

Synthesis of graphitic mesoporous carbon supported Ce-doped nickel catalyst for steam reforming of toluene

Graphitic mesoporous carbon (GMC) supported Ce-doped nickel catalyst was prepared by a simple incipient wetness impregnation and calcination method. The catalytic performance of the prepared catalyst was tested by catalytic steam reforming of toluene (a biomass tar model compound). Compared with mesoporous SBA-15 supported catalyst, the GMC supported catalyst has a higher toluene conversion efficiency of 98% at 700 °C and remained stable during 24 h of continuous reaction. The excellent catalytic performance is mainly attributed to the better dispersion of Ni nanoparticles on GMC support and the reduced carbon deposition because of the Ce-doping.

Investigation of competitive tar reforming using activated char as catalyst

Abstract Syngas tar removal is one of the biggest challenges for the gasification of biomass as a clean energy source. Efforts to understand the reforming mechanism of tar compounds have been continuous during the last decades. Kinetic studies often employ a single tar species, neglecting possible interactions between different tar compounds. On the other hand, char, a by-product from biomass gasification, presents opportunities to catalyze tar reforming. In this work, reforming experiments were conducted in a fixed-bed reactor using syngas with a known mixture of benzene (C6H6), toluene (C7H8) and naphthalene (C10H8). Hardwood char and an in-situ CO2-activated hardwood char were used as catalysts. The activated hardwood char exhibited the best reforming capabilities by converting 44% and 90% of the tars at 750 and 850°C, respectively, compared to 24% and 87% tar conversion obtained with the regular hardwood char at 750 and 850°C, respectively. From the experiments, a reduced mechanism model was proposed. This mechanism was used in computational simulations for analysis of the reaction kinetics, including possible catalyst selectivity. It was found that under a range of conditions, the benzene degradation is slower than its formation rate from toluene and naphthalene decomposition. This leads to increases in the benzene fraction at temperatures around 700°C. If the naphthalene and toluene concentrations are sufficient, benzene will accumulate even at high temperatures (around 800°C) regardless of residence times. It can be concluded that when benzene, toluene and naphthalene are present together, char favors the heterogeneous reforming of toluene and naphthalene, with benzene following an homogeneous reforming pathway.

New synthetic route for the production of mayenite support to enhance Ni resistance to coke deposition in the reforming of tar model compounds

Four nickel/mayenite catalysts were synthesized. Mayenite was prepared from different precursors, namely boehmite (AlO(OH)) + Ca(NO3)2·4H2O and gibbsite + Ca(OH)2, for each couple a specific procedure was followed. The effect of the Ni addition method was also evaluated, comparing wet impregnation and direct inclusion of nickel precursor during mayenite preparation. The obtained catalysts were characterized by XRD, BET, SEM/EDS and TPR. The Ni/mayenite catalysts were tested in steam reforming of toluene and pyrocatechol, chosen as tar model compounds. The experiments were conducted in a fixed-bed lab-scale atmospheric reactor, evaluating carbon conversion, hydrogen selectivity and stability. Characterization of the spent catalysts after toluene steam reforming experiments by XRD and DTG-TPO were performed to assess structural changes and carbon deposition. Kinetic parameters of toluene steam reforming were determined for the different catalysts.

Combined steam-dry reforming of toluene in syngas over CaNiRu/Al2O3 catalysts

Cracking, steam reforming, dry reforming, and combined steam and dry reforming of toluene in model syngas were performed using catalysts to simulate tar removal produced during biomass gasification...

Layered uniformly delocalized electronic structure of carbon supported Ni catalyst for catalytic reforming of toluene and biomass tar

Lignite rich in oxygen-containing species (OCSs) was employed as perfect ion-exchange material for high activity catalyst preparation. HCl treatment Shengli lignite (HSL) selectively removed the organic salt and improved capability of ion exchange. In this paper, highly desirable and layered carbon supported Ni catalyst was prepared by modified lignite. Thanks to the excellent role of Ni (1 1 1) plane and porous layered graphene-like delocalized electronic structure, specific structure of lignite provides an exchange platform in facilitating the Ni electron transfer during the catalytic reaction process. Ni loaded on HSL (Ni/HSL) showed the great catalytic activity and stability for reforming of toluene and biomass tar. Ni/HSL prepared at 650 °C shows the great activity and stability for toluene steam reforming (TSR) and biomass tar reforming (BTR). A series of instruments (XRD, SEM, TEM, H2-TPR, XPS, CO pulse adsorption, etc.) were employed for characterization. Based on these significant characterizations of catalyst, calculation of turnover frequency (TOF), and results of conversion of toluene and corncob tar. The results revealed the layered delocalized electronic structure of Ni/HSL, which has lower activation energy than other reported catalysts. Uniform dispersed catalyst was synthesized successfully for reforming of toluene and biomass tar.