BITS Faculty Publications

Permanent URI for this communityhttp://localhost:4000/handle/123456789/1867

Browse

Filters

2015 - 201912020 - 20243

Settings

Author: search.filters.author.Roy, BanasriSubject: search.filters.subject.Ethanol

Search Results

Now showing 1 - 4 of 4
  • No Thumbnail Available
    Item
    Tin and lanthanum modified Ni/CeO2 catalyst systems for low temperature steam reforming of ethanol
    (Elsevier, 2024-01) Roy, Banasri
    This work examines the Ni–Sn/Ce–La–O catalyst systems for low-temperature stream reforming of ethanol. Catalysts of 5 and 20 wt% metal loading, and different Ce:La ratios are prepared by ultra-sonication assisted solution combustion synthesis method. Catalysts at total metal loading 5 wt% with 33 and 67 at. % La and optimum Sn (Ni:Sn = 14:1) demonstrate better efficiency compared to the Ni/CeO2 catalysts. At 20 wt% metal loading and Ni:Sn = 1:1 atomic ratio, catalytic activity degrades. The best activity and stability are revealed for the N14S1(5)/CL21 catalyst with 5 wt.% total metal loading, Ni:Sn = 14:1, and Ce:La = 2:1 mol ratio. Physico-chemical characterizations (XRD, H2 -TPR, NH3-TPD, Raman, FESEM, TEM, XPS, N2 adsorption-desorption, DTA/TGA, etc.) are performed to understand the role of the metal loading, Sn, and La in the catalytic activity and coke deposition behavior.
  • No Thumbnail Available
    Item
    Study of preparation method and oxidization/reduction effect on the performance of nickel-cerium oxide catalysts for aqueous-phase reforming of ethanol
    (Elsevier, 2015-12) Roy, Banasri
    The effect of preparation method and oxidation state of the active metal on the catalytic activity of Ni–Ce–O catalysts was studied for aqueous phase reforming of ethanol. A sol-gel (SG) route and a solution combustion synthesis (SCS) method were used for the preparation of 10 wt% Ni loaded catalysts. The catalytic activity of three groups of catalysts; reduced at 425 °C (HR, metallic Ni), reduced at 1000 °C (FR, metallic Ni), and not reduced (NR, as NiO) were tested at different operating conditions. The difference in the metal particle sizes, governed by the preparation method, affects the catalytic efficiency most, not the reduced or oxidized state of Ni. The SG samples were superior for ethanol conversion and selectivity for H2 and CO2 compared to the SCS samples. The X-ray photoelectron spectroscopy (XPS) analysis of the samples demonstrated that the relative ratio of Ce2O3 to CeO2 increased inside the reactor. While Ni doping increases oxygen mobility in the Ce–O lattice, Ce3+ converts Ni2+ to metallic Ni inside the reactor. This can explain why the reduction stage for Ni–Ce–O system in APR is irrelevant. Higher oxygen mobility through the support helps oxidation of CO to CO2 leading to improved catalytic performance.
  • No Thumbnail Available
    Item
    Low temperature steam reforming of ethanol over cobalt doped bismuth vanadate [Bi4(V0.90Co0.10)2O11-δ (BICOVOX)] catalysts for hydrogen production
    (Elsevier, 2021-01) Roy, Banasri
    The atmospheric pressure low temperature steam reforming of ethanol over Bi4(V0.90Co0.10)2O11-δ (BICOVOX) catalysts, synthesize by a solution combustion synthesis method and calcined at 400, 600 and 800 °C, has been investigated at different reactor temperatures, H2O: EtOH molar ratios and feed flow rates. For fresh catalysts amount, crystallinity and particle size of pure γ-BICOVOX phase is observed to increase with increasing calcination temperature. Phase purity and crystallinity of the catalysts are almost retained till 30 h of activity study with some amount of carbon formation as derived from XRD, XPS, FESEM and simultaneous DTA-TGA study. Catalyst calcined at 600 °C (BICOVOX-600) exhibits the highest ethanol conversion (100%) with maximum H2 selectivity (80%) under reaction conditions of 400 °C, 23:1H2O: EtOH molar ratio and 0.35 cc min−1 feed flow rate. The maximum O2− vacancy present in lattice and lowest coke deposition could explain the best performance of BICOVOX-600 catalyst.
  • No Thumbnail Available
    Item
    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.