Browsing by Author "Roy, Banasri"

Now showing 1 - 20 of 61

Aqueous-phase reforming of n-BuOH over Ni/Al2O3 and Ni/CeO2 catalysts
(Elsiever, 2011-12-15) Roy, Banasri
The aqueous-phase reforming (APR) of n-butanol (n-BuOH) over Ni(20 wt%) loaded Al2O3 and CeO2 catalysts has been studied in this paper. Over 100 h of run time, the Ni/Al2O3 catalyst showed significant deactivation compared to the Ni/CeO2 catalyst, both in terms of production rates and the selectivity to H2 and CO2. The Ni/CeO2 catalyst demonstrated higher selectivity for H2 and CO2, lower selectivity to alkanes, and a lower amount of C in the liquid phase compared to the Ni/Al2O3 sample. For the Ni/Al2O3 catalyst, the selectivity to CO increased with temperature, while the Ni/CeO2 catalyst produced no CO. For the Ni/CeO2 catalyst, the activation energies for H2 and CO2 production were 146 and 169 kJ mol−1, while for the Ni/Al2O3 catalyst these activation energies were 158 and 175 kJ mol−1, respectively. The difference of the active metal dispersion on Al2O3 and CeO2 supports, as measured from H2-pulse chemisorption was not significant. This indicates deposition of carbon on the catalyst as a likely cause of lower activity of the Ni/Al2O3 catalyst. It is unlikely that carbon would build up on the Ni/CeO2 catalyst due to higher oxygen mobility in the Ni doped non-stoichiometric CeO2 lattice. Based on the products formed, the proposed primary reaction pathway is the dehydrogenation of n-BuOH to butaldehyde followed by decarbonylation to propane. The propane then partially breaks down to hydrogen and carbon monoxide through steam reforming, while CO converts to CO2 mostly through water gas shift. Ethane and methane are formed via Fischer–Tropsch reactions of CO/CO2 with H2.
Assessment of bimetallic Zn/Fe0 nanoparticles stabilized Tween-80 and rhamnolipid foams for the remediation of diesel contaminated clay soil
(Elsevier, 2023-01) Roy, Banasri; Chattopadhyay, Pradipta
Diesel contamination of soil due to oil spills, disposal of refinery waste, oil exploration constitutes a major environmental problem. This paper reports the remediation of diesel contaminated clay soil using Zn/Fe0 bimetallic nanoparticle stabilized Rhamnolipid (RMLP) and Tween-80 (TW-80) surfactant foams. Fe0, and Zn (x wt%)/Fe0 (x = 0.2, 2.0, and 10.0) bimetallic nanoparticles are synthesized by using sodium borohydride reduction method. The average particle size (from FESEM) is calculated to be 62, 57, 42 and 35 nm for the Fe0, Zn (0.2)/Fe0, Zn (2)/Fe0 and Zn (10)/Fe0 nanopowders, respectively. The highest foamability and foam stability of 109.6 and 108.5 mL, respectively are observed for the RMLP (12 mg/l) surfactant foam stabilized with 6 mg/l Zn (10)/Fe0 nanoparticles. The surface tension values reduce to the lowest value of 28.1 and 31.4 mN/m with the addition of 6 mg/l of Zn (10)/Fe0 powder in RMLP and TW-80 solutions of 12 mg/l, respectively. The maximum diesel removal efficiency of 83.8 and 59%, is achieved by RMLP (12 mg/l) foam stabilized by Zn (10)/Fe0 nanoparticles (6 mg/l) for the clay soil contaminated with 100 and 500 μl/g of diesel, respectively. The physicochemical properties of the nanoparticles are studied to explain the foam properties and the remediation behavior. These findings regarding the nanoparticle stabilized foams can offer a cost-effective environment friendly commercial solution for soil remediation in the future.
BINIVOX catalyst for hydrogen production from ethanol by low temperature steam reforming (LTSR)
(Springer, 2017-11) Roy, Banasri; Mohanta, Hare Krishna
Nickel doped bismuth vanadate [;BINIVOX] calcined at (BINIVOX-800) catalyst is prepared by a solution combustion method. The catalytic activity study is carried in the temperature range of 250–, and with the molar feed ratios of water: ethanol at 23:1 and 2.5:1. The study reveals an increase in the ethanol conversion and selectivity of carbon dioxide & hydrogen but a decrease in the selectivity of carbon monoxide and methane with an increase in temperature and water: ethanol mole ratio. Fresh and used catalysts are characterized using DTA, TGA, XRD and FTIR. XRD results reveal that the fresh catalyst is phase pure γ-BINIVOX. The phase purity and crystallinity of the catalyst is retained after 30 h of activity study.
Carbon Dioxide Adsorption over Activated Biocarbons Derived from Lemon Peel
(MDPI, 2024-09) Roy, Banasri
The rising concentration of CO2 in the atmosphere is approaching critical levels, posing a significant threat to life on Earth. Porous carbons derived from biobased materials, particularly waste byproducts, offer a viable solution for selective CO2 adsorption from large-scale industrial sources, potentially mitigating atmospheric CO2 emissions. In this study, we developed highly porous carbons from lemon peel waste through a two-step process, consisting of temperature pretreatment (500 °C) followed by chemical activation by KOH at 850 °C. The largest specific surface area (2821 m2/g), total pore volume (1.39 cm3/g), and micropore volume (0.70 cm3/g) were obtained at the highest KOH-to-carbon ratio of 4. In contrast, the sample activated with a KOH-to-carbon ratio of 2 demonstrated the greatest micropore distribution. This activated biocarbon exhibited superior CO2 adsorption capacity, reaching 5.69 mmol/g at 0 °C and 100 kPa. The remarkable adsorption performance can be attributed to the significant volume of micropores with diameters smaller than 0.859 nm. The Radke–Prausnitz equation, traditionally employed to model the adsorption equilibrium of organic compounds from liquid solutions, has been shown to be equally applicable for describing the gas–solid adsorption equilibrium. Furthermore, equations describing the temperature dependence of the Radke–Prausnitz equation’s parameters have been developed.
Carbonaceous catalysts (biochar and activated carbon) from agricultural residues and their application in production of biodiesel: A review
(Elsevier, 2024-03) Chatterjee, Somak; Roy, Banasri
Carbonaceous catalysts obtained from agricultural residue could have potential in the production of biofuels such as biodiesel. This review paper discusses the preparation conditions (temperature, heating rate, hold time, inert gas flow rate, etc play key roles in development of textural characteristics of the catalysts) and functionalization methods of biochar and activated carbon derived from agricultural residues and their application to produce biodiesel. Research works reported in achieving maximum yield of biodiesel in terms of variable precursors, alcohol-to-oil ratio, reaction time and temperatures have been profoundly tabulated. Effect of textural properties of the biochar and activated carbon (such as surface area, total pore volume, average pore size, and functional group attached with the catalyst) on the biodiesel yield are examined. Studies on Regeneration and reusing of the spent catalysts are carefully inspected. The economic evaluation studies for the biochar and activated carbon and the applications of these for biodiesel production are scrutinized. Finally, the strategies to increase biomass and catalyst productivity, future prospect and research directions to enhance biofuel/biodiesel production and for the development of biochar and activated carbon from agricultural residues for sustainable biodiesel production is suggested.
Comparison of zero-valent iron and iron oxide nanoparticle stabilized alkyl polyglucoside phosphate foams for remediation of diesel-contaminated soils
(Elsiever, 2019-06-15) Chattopadhyay, Pradipta; Roy, Banasri
Stable surfactant foam might play a vital role in the effective remediation of diesel oil contaminated soil-a major environmental hazard. This paper, first of its kind, is reporting the remediation of diesel-contaminated desert soil, coastal soil and clay soil by aqueous alkylpolyglucoside phosphate (APG-Ph) surfactant foams stabilized by Fe0 and Fe3O4 nanoparticles. Zero-valent iron (Fe0, ∼28 nm) and iron oxide (Fe3O4, ∼20 nm) nanoparticles are synthesized by liquid-phase reduction and precipitation methods, respectively. The effect of these nanoparticles on foamability, foam stability, surface tension and remediation of diesel-contaminated soils are examined at various concentrations (volume %) of alkylpolyglucoside phosphate (APG-Ph) surfactant and nanoparticles (mg/l). The maximum values of foamability and foam stability recorded for 0.1 vol % APG-Ph foam stabilized by 3.5 mg/l Fe0 are 108.3 and 110.4 mL, respectively. At the same conditions, the Fe3O4 results in 99.4 and 87.5 mL, respectively, depicting the better performance of Fe0. Reduction in surface tension of 0.1 vol % APG-Ph solution (50.75 mN/m) with the addition of 3.5 mg/l Fe0 (9.51 mN/m) and Fe3O4 (19.45 mN/m) nanoparticle is observed. Both the nanoparticles enhance remediation. The foam formed with 0.1 vol % APG-Ph and stabilized by 3.5 mg/l Fe0 shows the maximum diesel removal efficiency of 95.3, 94.6, and 57.5% for coastal soil, desert soil and clay soil, respectively. On the other hand, Fe3O4 (3.5 mg/l) stabilized APG-Ph foam of the same concentration shows merely 76.0, 79.6 and 51.6% diesel removal efficiency for coastal soil, desert soil, and clay soil, respectively. The rate of diesel removal by zero-valent iron and iron oxide nanoparticle stabilized foams are found to be well described by the first order kinetic model. Higher foamability, foam stability, and reducing capacity accompanying lower surface tension, compared to those of the Fe3O4 nanoparticle stabilized foam, could explain higher diesel removal efficiency of the Fe0 nanoparticle stabilized foam.
Controlling the Size and Morphology of TiO2 Powder by Molten and Solid Salt Synthesis
(Wiley, 2008-08-12) Roy, Banasri
Nano and submicrometer scale titanium oxide (TiO2) powders were synthesized by solid and molten salt synthesis (SSS and MSS) from amorphous titanium hydroxide precipitate. Sodium chloride (NaCl) and dibasic sodium phosphate (Na2HPO4·2H2O, DSP) separately or as mixture with different weight ratios were used as the salts. At the eutectic salt composition (20% DSP/80% NaCl), the microstructure and phase composition of the TiO2 was changed from equiaxed nanoparticles of anatase with size ∼40–50 nm, to mixed microstructure of bundle and acicular particles of rutile with 0.05–0.2 μm diameter, 6–10 μm length, and aspect ratio 20–60 depending on treatment time and temperature. At high temperature (825°C) and long time (30 h), microstructural differences were significant for the powders treated with different salts. Particle morphologies ranged from equiaxed, to acicular, to bundles, to nanofibers with very high aspect ratio. At lower treatment temperature (725°C) for shorter time (3 h), the morphology of the products did not change with different salt compositions, but the crystallite sizes changed appreciably. Different starting titanium precursors influenced particle size at lower temperature and time. Titanium hydroxide heat treated without salt resulted in significant grain growth and fused secondary particles, as compared with more finely separated and lightly agglomerated powders resulting from SSS and MSS treatments.
Deactivation study of the BICOVOX catalysts used in low temperature steam reforming of ethanol for H2 production
(Elsevier, 2021-10) Roy, Banasri
The γ-BICOVOX, having high O2- mobility at low temperature (≤300 °C), might be a good catalyst for hydrogen production by low temperature steam reforming (LTSR) of ethanol. LTSR (at atmospheric pressure) of ethanol over Bi4(V0.90Co0.10)2O11-δ (BICOVOX) catalysts (synthesized by a solution combustion method and calcined at 400, 600 and 800 °C) has been investigated at the reaction conditions of 400 °C, H2O: EtOH molar ratio 23:1 and 0.35 ml min−1 feed flow rate. Catalysts remain active for the time period of ~30 h and after that start to deactivate. According to the XRD analysis γ- BICOVOX decomposes to BiVO4, Bi2O3, and Bi phases due to a reducing environment present inside the reactor. According to the XPS analysis, decrease in γ- BICOVOX amount diminishes the oxygen vacancy in the lattice. This probably causes significant decline in O2- mobility through the lattice and consequently carbon deposition occurs (derived from XPS, FESEM & DTGA) leading to an almost complete deactivation of the catalysts within 150 h.
Development of Ni–Sn/Al2O3 Nano Catalysts for H2 Production from Biomass by Aqueous Phase Reforming
(Igenta, 2014-07) Roy, Banasri
Preparation and characterization of nano Ni–Sn/Al2O3 catalysts prepared by Co-precipitation technique has been reported in this paper. Two set of samples have been designed; in first one the metal/support catalyst is directly precipitated from solution mixture of precursors as one pot synthesis, while for the second one, Al2O3 support is prepared by precipitation method and then metal is loaded by standard wet impregnation. Aluminum nitrate, nickel nitrate, tin chloride, and ammonia solution are used as the starting materials. Investigations regarding the structure - property relations are being carried out through TGA, FTIR, and XRD which will be discussed in detail.
Dual reforming of model biogas for syngas production on Ni/γ-Al2O3 and Ni-C/ZSM-5 cordierite monolith catalysts
(Elsevier, 2023) Roy, Banasri; Srinivas, Appari
This work attempts to convert the model biogas on Ni/γ-Al2O3 and Ni-C/ZSM-5 into syngas using a dual-bed catalytic monolith reactor. The monolith is wash-coated with alumina and ZSM-5, respectively, followed by Ni and glucose-assisted Ni (Ni-C) loading using the wet impregnation technique. These two monoliths are loaded in an Inconel reactor and placed in a two-zone heating furnace. In dual reforming, either Ni/γ-Al2O3 or Ni-C/ZSM-5 monolith is used for dry reforming, and then Ni/γ-Al2O3 is used for steam reforming. A distance of ∼ 10 cm is maintained between these two monoliths. The exhaust gases from the first monolith are combined with steam before passing to the second monolith. The biogas reforming is carried out for a feed ratio (CH4:CO2) 1.5, GHSV of 1440 h−1 and 2880 h−1, at 800℃ and 1 atm pressure. The steam to CH4 ratio (S/C) is optimized to maximize the conversions (greater than80 %) of both CH4 and CO2. It was observed that the CH4 conversions increase with an increased S/C ratio due to the steam reforming in the second monolith. The TGA results show 7.6 % carbon formation on Ni-C/ZSM-5 and 35 % on Ni/γ-Al2O3 in dry reforming on the first monolith bed.
Effect of acceptor and donor dopants on polarization components of lead zirconate titanate thin films
(AIP, 2001-01-11) Roy, Banasri
ABSTRACT We have compared the magnitudes of reversible and irreversible polarization components of sol–gel-derived Nd3+- and Fe3+-doped PZT (53/47) thin films on platinized silicon substrates. Beyond the switching field, it was found that the reversible component of the polarization remains almost constant both for donor- (Nd3+) and acceptor- (Fe3+) doped PZT films. The irreversible polarization component reduces with the increase in Nd3+ content, whereas it increases until 3 at. % Fe3+-doped PZT thin films. The dielectric behavior of these films at subswitching fields was analyzed in terms of Rayleigh law. The inverse of the Raleigh coefficient (υ) was considered as a measure of the obstacle for the domain-wall motion. In the case of Fe-doped PZT, the inverse of the Raleigh coefficient (υ) shows a declining linearity with Fe content, which may be found exactly opposite to that observed for Nd-doped PZT. The observed results are explained in terms of the nature of the defect-domain-wall interaction of acceptor-and-donor-doped PZT thin films. Studies indicated that in the case of Fe-doped PZT films, the possible defect interaction initiates only above 2 at. % and it was found to be much lower in magnitude in comparison with the Nd doping.
Effect of Calcination Time on the Catalytic Activity of Ni/γ-Al2O3 Cordierite Monolith for Dry Reforming of Biogas
(Elsevier, 2021-02) Roy, Banasri; Srinivas, Appari
Ni/γ-Al2O3 wash coated cordierite monolith catalysts are calcined in air at 800 °C for 4, 10, and 20 h in order to study the effect of calcination time on the activity of the catalysts for dry reforming of model biogas. Catalytic activity studies are performed at 800 °C with three different CH4/CO2 ratios of 1.0, 1.5, and 2.0. The catalyst calcined for the longest time (C-20) displays higher stability and activity in terms of CH4 and CO2 conversion compared to those calcined for 4 h (C-4) and 10 h (C-10). XRD data and TPR analysis detect the maximum amount of NiAl2O4/MgAl2O4 phases and strongest metal-support interaction, respectively, for the C-20 sample. FESEM reveals the particle size of the calcined and reduced C-20 sample to be smaller than that of the C-4 and C-10 samples. Whereas, H2 pulse-chemisorption characterization demonstrates the highest metal surface area, metal dispersion, and smallest Ni particle size for the C-20 catalyst. While, no carbon deposition on any catalyst occurs for the CH4/CO2 ratio of one, lowest amount of carbon nanotubes is formed on the C-20 sample for the CH4/CO2 ratio of 1.5 and 2.0, as observe by DTA-TGA. EDX reveals concentration variation of Mg and Si from the cordierite monolith wall along the thickness of the coating for all the samples. In addition, the maximum amount of these elements is observed for the calcined C-20 catalyst coating. These implies that the diffusion of Mg and Si from the cordierite monolith to the catalyst coating during calcination contribute significantly in controlling the physicochemical properties of the catalysts. As a result, the higher stability and activity of the C-20 could be attributed to the formation of higher amount of the Ni– Mg- alumina spinel complex in the catalyst coating during longer calcination time, which leads to the improved metal-support interaction and higher nickel dispersion over monolith.
Effect of Calcination Time on the Catalytic Activity of Ni/γ-Al2O3 Cordierite Monolith for Dry Reforming of Biogas
(Elsiever, 2020) Srinivas, Appari; Roy, Banasri
Ni/γ-Al2O3 wash coated cordierite monolith catalysts are calcined in air at 800 °C for 4, 10, and 20 h in order to study the effect of calcination time on the activity of the catalysts for dry reforming of model biogas. Catalytic activity studies are performed at 800 °C with three different CH4/CO2 ratios of 1.0, 1.5, and 2.0. The catalyst calcined for the longest time (C-20) displays higher stability and activity in terms of CH4 and CO2 conversion compared to those calcined for 4 h (C-4) and 10 h (C-10). XRD data and TPR analysis detect the maximum amount of NiAl2O4/MgAl2O4 phases and strongest metal-support interaction, respectively, for the C-20 sample. FESEM reveals the particle size of the calcined and reduced C-20 sample to be smaller than that of the C-4 and C-10 samples. Whereas, H2 pulse-chemisorption characterization demonstrates the highest metal surface area, metal dispersion, and smallest Ni particle size for the C-20 catalyst. While, no carbon deposition on any catalyst occurs for the CH4/CO2 ratio of one, lowest amount of carbon nanotubes is formed on the C-20 sample for the CH4/CO2 ratio of 1.5 and 2.0, as observe by DTA-TGA. EDX reveals concentration variation of Mg and Si from the cordierite monolith wall along the thickness of the coating for all the samples. In addition, the maximum amount of these elements is observed for the calcined C-20 catalyst coating. These implies that the diffusion of Mg and Si from the cordierite monolith to the catalyst coating during calcination contribute significantly in controlling the physicochemical properties of the catalysts. As a result, the higher stability and activity of the C-20 could be attributed to the formation of higher amount of the Ni– Mg- alumina spinel complex in the catalyst coating during longer calcination time, which leads to the improved metal-support interaction and higher nickel dispersion over monolith.
Effect of neodymium (Nd) doping on the dielectric and ferroelectric characteristics of sol-gel derived lead zirconate titanate (53/47) thin films
(AIP, 2001-01-12) Roy, Banasri
The results of the studies on the effect of rare earth Nd doping on the phase formation behavior and electrical properties of sol-gel derived Pb1.05(Zr0.53Ti0.47)O3 (PZT) thin films are presented. The perovskite phase is obtained up to 5 at. % doping and beyond that pyrochlore phase was found to coexist with the perovskite phase in all the films. The transition temperature of undoped lead zirconate titanate (PZT) film was found to be reduced with Nd doping. The Nd doped films also exhibited typical relaxor-type behavior and a diffuse phase transition, similar to that observed in relaxor materials. The introduction of Nd into the PZT lattice probably introduces disorder in the B site of ABO3 lattice, which causes the observed dielectric relaxation. Efforts were made to isolate the irreversible component contributions in low field dielectric and high field polarization switching behavior. REFERENCES
Effect of preparation method on the performance of the Ni/Al2O3 catalysts for aqueous-phase reforming of ethanol: Part I-characterization
(INFOFNA, 2012) Roy, Banasri
Effect of rare earth doping on sol-gel derived PZT thin films
(Taylor & Francis, 2000-09-04) Roy, Banasri
We have studied the effect of rare earth dopants (Nd, Gd and Ce) on the phase formation behavior and electrical properties of sol-gel derived Pb1.05(Zr0.53Ti0.47)O3 thin films. In all these films the perovskite phase is obtained up to 5 at% doping and beyond that pyrochlore phase was found to coexist with the perovskite phase. Ce and Gd doping(1-2 at%) exhibited improved ferroelectric and dielectric properties as compared to the undoped PZT films. Nd doping (2 at%) was found to be effective to increase the retained switchable polarization of undoped PZT from 63% to 84%. The transition temperature of undoped PZT film was found to be reduced with Nd doping. The Nd doped films also exhibited typical relaxor behavior and a diffuse phase transition, characteristic of the relaxor material. Introduction of Nd into the PZT lattice probably introduces disorder in the B site of ABO3 lattice which causes the observed relaxor behavior
Effect of salt composition on photovoltaic performance of the dye-sensitized solar cells prepared from nano anatase TiO2 powder using NaCl–Na2HPO4·2H2O salt matrices
(Springer, 2011-12) Roy, Banasri
Photovoltaic performances of dye-sensitized solar cells based on mesoporous TiO2 coating of nanocrystalline anatase prepared by solid salt synthesis were investigated in this study. Three different salt compositions pure NaCl, NaCl and DSP 50–50 wt% mixture, and pure DSP have been used as the reaction mediums. The best photovoltaic performances were obtained for the device made using the powder from DSP matrix. The dye-sensitized solar cells built from DSP and NaCl50 powders showed 13.8 and 6.5% improvements in the short-circuit current density, and 34 and 20% improvement in overall efficiency, respectively, than those of the cell made from Degussa P-25 powder. These results have been explained from the microstructural point of view of the powders. Electron microscopy, XRD, Raman, and nitrogen adsorption–desorption studies showed that the coatings made from the powders obtained via NaCl 50 and DSP salt medium treatments were of smaller sizes and contained higher densities of narrower mesoporous distribution than that obtained by the coating from NaCl and no-salt-synthesized materials.
Effect of variable conditions on steam reforming and aqueous phase reforming of n-butanol over Ni/CeO2 and Ni/Al2O3 catalysts
(Elsevier, 2014-12) Roy, Banasri
A comparison of aqueous phase reforming (APR) and steam reforming (SR) of n-butanol (n-BuOH) over Ni(20 wt%) loaded Al2O3 and CeO2 catalysts has been discussed in this paper. The BuOH conversion increases as the system pressure decreases in APR and SR. For both catalysts, the H2 and CO2 selectivity increased as the pressure increased in SR, reached a maximum at the bubble point pressure, and then decreased in the APR region. The Ni/CeO2 catalyst demonstrated higher selectivity for H2 and CO2than the Ni/Al2O3 catalyst during SR, which are consistent with the results of our previous publication on APR of n-butanol (n-BuOH) over similar catalysts. Unlike in APR, the Ni/CeO2 catalyst produced CO in SR. For both of the catalysts, the activation energies for H2 and CO2 production and BuOH conversion were lower in SR than that in APR. The proposed primary reaction pathway for reforming of BuOH on both catalysts is the same for APR and SR. The n-BuOH dehydrogenated to butaldehyde followed by decarbonylation to propane. Then the propane is steam reformed to hydrogen and carbon monoxide. The CO converts to CO2 mostly through water gas shift.
Effect of variable conditions on steam reforming and aqueous phase reforming of n-butanol over Ni/CeO2 and Ni/Al2O3 catalysts
(Elsiever, 2014-12-01) Roy, Banasri
A comparison of aqueous phase reforming (APR) and steam reforming (SR) of n-butanol (n-BuOH) over Ni(20 wt%) loaded Al2O3 and CeO2 catalysts has been discussed in this paper. The BuOH conversion increases as the system pressure decreases in APR and SR. For both catalysts, the H2 and CO2 selectivity increased as the pressure increased in SR, reached a maximum at the bubble point pressure, and then decreased in the APR region. The Ni/CeO2 catalyst demonstrated higher selectivity for H2 and CO2than the Ni/Al2O3 catalyst during SR, which are consistent with the results of our previous publication on APR of n-butanol (n-BuOH) over similar catalysts. Unlike in APR, the Ni/CeO2 catalyst produced CO in SR. For both of the catalysts, the activation energies for H2 and CO2 production and BuOH conversion were lower in SR than that in APR. The proposed primary reaction pathway for reforming of BuOH on both catalysts is the same for APR and SR. The n-BuOH dehydrogenated to butaldehyde followed by decarbonylation to propane. Then the propane is steam reformed to hydrogen and carbon monoxide. The CO converts to CO2 mostly through water gas shift.
Effects of metal loading and support modification on the low-temperature steam reforming of ethanol (LTSRE) over the Ni–Sn/CeO2 catalysts
(Elsevier, 2023-05) Roy, Banasri; Srinivas, Appari
This article presents the effect of metal loading and support modification with MgO on low-temperature steam reforming of ethanol (LTSRE) over Ni–Sn/CeO2 catalysts prepare by a single-pot solution combustion synthesis (SCS) method. Atmospheric pressure activity study of these catalysts (0.5 g) is performed at different temperatures (200–400 °C), H2O:EtOH = 12: 1 mol ratio, and feed flow rate 0.1 ml/min. After 10 h TOS at 400 °C, NiSn(5)/CM12 catalyst with 5 wt.% total metal loading, optimal Sn (Ni:Sn = 14:1), and Ce:Mg = 1:2 mol ratio shows EtOH conversion 100% and H2 selectivity 70% with low coke deposition. Physicochemical characterizations (XRD, Raman, FESEM, TEM, and N2 adsorption-desorption) reveal that addition of MgO in CeO2 and an optimal amount of Sn decrease both Ni and support particle sizes while oxygen storage capacity (OSC) of the support increases (by XPS). Alkaline characteristics of MgO reduces support's acidity and improves active metal-support interaction, as evaluated by NH3-TPD and H2-TPR.