@article { ISI:000228226800025, title = {Carbon-free dry reforming of methane to syngas over NdCoO3 perovskite-type mixed metal oxide catalyst}, journal = {Catalysis Letters}, volume = {100}, number = {3-4}, year = {2005}, month = {APR}, pages = {271-276}, publisher = {SPRINGER}, type = {Article}, address = {233 SPRING ST, NEW YORK, NY 10013 USA}, abstract = {

CoNdOx (Co/Nd = 1) is a highly promising catalyst for the carbon-free CO2 reforming of methane. Influence of the Co/Nd ratio on the catalyst performance in the CO2 reforming and also on the crystalline phases and reduction by temperature programmed reduction (TPR) of the CoNdOx catalyst has also been investigated. The CoNdOx (CoNd = 1.0) catalyst consisted of mainly NdCoO3 perovskite- type mixed metal oxide and it showed not only a high resistance to carbon formation at different process conditions ( viz. temperature = 750 - 900 degrees C and gas hourly space velocity (GHSV) = 10000 - 50000 cm(3) g(-1) h(-1)) but also high activity and selectivity in the CO2 reforming process. The high resistance to carbon formation for this catalyst is attributed mostly to strong metal (Co degrees) - support (Nd2O3) interactions.

}, keywords = {CO2 reforming of methane to syngas, CoNdOx catalyst, NdCoO3 perovskite, resistance to carbon formation in CO2 reforming}, issn = {1011-372X}, doi = {10.1007/s10562-004-3467-0}, author = {Choudhary, Vasant R. and Mondal, Kartick C. and Mamman, Ajit Singh and Joshi, Upendra A.} } @article { ISI:000230122100004, title = {High-temperature stable and highly active/selective supported NiCoMgCeOx catalyst suitable for autothermal reforming of methane to syngas}, journal = {Journal of Catalysis}, volume = {233}, number = {1}, year = {2005}, month = {JUL}, pages = {36-40}, publisher = {ACADEMIC PRESS INC ELSEVIER SCIENCE}, type = {Article}, address = {525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA}, abstract = {

Low-surface-area, macroporous, zirconia-haffnia-supported NiCoMgOx and NiCoMgCeOx (Ni/Co/Mg/Ce = 1/0.2/1.2/0.0 or 1.2) catalysts, precalcined at high temperature ( 1400 degrees C for 4 h), showed both high activity (\> 98\% conversion) and selectivity ( \> 95\%) in the catalytic partial oxidation of methane (CPOM) to syngas. Their performance remained unchanged even after they were subjected to higher temperature (\> 2000 degrees C for 30 min) or a number of high-temperature (\> 2000 degrees C) shocks, due to their direct exposure to an oxyacetylene flame. The supported NiCoMgCeOx, however, showed superior performance in the steam and CO2 reforming reactions because of its much higher lattice oxygen mobility. Hence it is more suitable for the autothermal reforming of methane. (c) 2005 Elsevier Inc. All rights reserved.

}, keywords = {autothermal reforming of methane, Catalyst, catalytic partial oxidation of methane, CO2 reforming of methane, high-temperature stable supported NiCoMgCeOx catalyst, steam reforming of methane, zirconia-haffnia-supported NiCoMgCeOx catalysts, zirconia-haffnia-supported NiCoMgOx}, issn = {0021-9517}, doi = {10.1016/j.jcat.2005.04.019}, author = {Choudhary, Vasant R. and Mondal, Kartick C. and Mamman, Ajit Singh} } @article { ISI:000230521800024, title = {Simultaneous conversion of methane and methanol into gasoline over bifunctional Ga-, Zn-, In-, and/or Mo-modified ZSM-5 zeolites}, journal = {Angewandte Chemie-International Edition}, volume = {44}, number = {28}, year = {2005}, month = {JUN}, pages = {4381-4385}, publisher = {WILEY-V C H VERLAG GMBH}, type = {Article}, address = {PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY}, keywords = {gallium, heterogeneuos catalysis, methane activation, Molybdenum, zeolites}, issn = {1433-7851}, doi = {10.1002/anie.200500694}, author = {Choudhary, Vasant R. and Mondal, Kartick C. and Mulla, Shafeek Abdul Rashid} } @article { ISI:000238812600009, title = {CO2 reforming of methane combined with steam reforming or partial oxidation of methane to syngas over NdCoO3 perovskite-type mixed metal-oxide catalyst}, journal = {Applied Energy}, volume = {83}, number = {9}, year = {2006}, month = {SEP}, pages = {1024-1032}, publisher = {ELSEVIER SCI LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND}, abstract = {

CO2 reforming with simultaneous steam reforming or partial oxidation of methane to syngas over NdCoO3 perovskite-type mixed metal oxide catalyst (prereduced by H-2) at different process conditions has been investigated. In the simultaneous CO2 and steam reforming, the conversion of methane and H2O and also the H-2/CO product ratio are strongly influenced by the CO2/H2O feed-ratio. In the simultaneous CO2 reforming and partial oxidation of methane, the conversion of methane and CO2, H-2 selectivity and the net heat of reaction are strongly influenced by the process parameters (viz. temperature, space velocity and relative concentration of O-2 in the feed). In both cases, no carbon deposition on the catalyst was observed. The reduced NdCoO3 perovskite-type mixed-oxide catalyst (Co dispersed on Nd2O3) is a highly promising catalyst for carbon-free CO2 reforming combined with steam reforming or partial oxidation of methane to syngas. (c) 2005 Published by Elsevier Ltd.

}, keywords = {Co/Nd2O3 catalyst, methane, NdCoO3 perovskite-type mixed metal-oxide catalyst, Oxy-CO2 reforming of methane, simultaneous CO2 and steam reforming of methane}, issn = {0306-2619}, doi = {10.1016/j.apenergy.2005.09.008}, author = {Choudhary, Vasant R. and Mondal, Kartick C.} } @article { ISI:000238258500019, title = {CO2 reforming of methane to syngas over CoOx/MgO supported on low surface area macroporous catalyst carrier: Influence of Co loading and process conditions}, journal = {Industrial \& Engineering Chemistry Research}, volume = {45}, number = {13}, year = {2006}, month = {JUN}, pages = {4597-4602}, publisher = {AMER CHEMICAL SOC}, type = {Article}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

The effect of Co loading (5-30 wt \%) and process parameters ( reduction pretreatment, reaction temperature, and space velocity) have been investigated over CoOx/MgO(5\%)/SA-5205 catalyst for the CO2 methane reforming process. The Co loading had a profound effect on the methane conversion and the hydrogen selectivity ( initial and time-on-stream activity) for the unreduced catalysts. While negligible methane conversion was observed for the 5 and 10 wt \% Co loading catalyst, methane conversions \> 95\% were obtained over the high Co loading ( 20 and 30 wt \%) catalysts; hydrogen selectivity followed the same trend as methane conversion. The Co loading level had a relatively smaller influence in the case of the reduced catalysts. While the 5 wt \% Co catalyst showed low methane conversion activity (\< 30\%), the 10 wt \% Co catalyst showed methane conversion levels comparable to those of the high Co loading catalysts. The high Co loading catalysts showed an excellent time-on-stream performance for the CO2 methane reforming reaction. X-ray diffraction and temperature-programmed reduction experiments indicate that the interesting activity behavior exhibited by the catalysts is related to the different phases ( and their reducibility) present in the catalysts at different Co loadings. The hydrogen selectivity was found to decrease with decreasing reaction temperature and increasing space velocity due to the increased simultaneous occurrence of the reverse water-gas shift reaction along with the CO2 reforming reaction.

}, issn = {0888-5885}, doi = {10.1021/ie060260a}, author = {Choudhary, Vasant R. and Mondal, Kartick C. and Choudhary, Tushar V.} } @article { ISI:000239295800003, title = {Methane reforming over a high temperature stable-NiCoMgOx supported on zirconia-hafnia catalyst}, journal = {Chemical Engineering Journal}, volume = {121}, number = {2-3}, year = {2006}, month = {AUG}, pages = {73-77}, publisher = {ELSEVIER SCIENCE SA}, type = {Article}, address = {PO BOX 564, 1001 LAUSANNE, SWITZERLAND}, abstract = {

The unusually high temperature stable NiCoMgOx (Ni/Co/Mg: 1:0.2:1.2)/zirconia-hafnia catalyst has been investigated for syngas generation via the catalytic partial oxidation of methane (CPOM), oxidative steam reforming of methane (OSRM) and oxidative CO2 reforming of methane (OCRM) processes. The catalyst, even when calcined at 1400 degrees C for 4 h, showed excellent activity/selectivity for the CPOM, OSRM and the OCRM reactions. On account of its high thermal stability, hot spots in the catalyst bed and/or high temperatures prevailing at the catalyst surface during the oxy-reforming processes would have little or no effect on the catalytic activity/selectivity of the NiCoMgOx/zirconia-hafnia catalyst, thus making the catalyst suitable even for operating under adiabatic conditions. While the selectivity for CO increased considerably with increasing reaction temperature for the CPOM process, the selectivity for H-2 was affected to a much lesser extent. The selectivity for CO and H-2 in the CPOM reaction was found to decrease with increasing space velocity; the H-2 selectivity was however affected to a greater extent. For the OSRM process, the H2O/CH4 ratio profoundly influenced the H-2/CO ratio and the heat of the reaction. Depending on the H2O/CH4 ratio, the OSRM process could be operated in a mildly exothermic, thermoneutral or mildly endothermic mode. The CO2 conversion increased rapidly with increasing OCRM temperature and correspondingly the exothermicity of the OCRM reaction was found to decrease with increasing reaction temperature. At 900 degrees C, the OCRM reaction was mildly exothermic and provided high methane conversion and syngas selectivity. (c) 2006 Elsevier B.V. All rights reserved.

}, keywords = {high temperature stable catalyst, methane, oxy-dry reforming, oxy-steam reforming, Partial oxidation}, issn = {1385-8947}, doi = {10.1016/j.cej.2006.05.007}, author = {Choudhary, Vasant R. and Mondal, Kartick C. and Choudhary, Tushar V.} } @article { ISI:000238162900006, title = {Non-catalytic pyrolysis of ethane to ethylene in the presence of CO2 with or without limited O-2}, journal = {Journal of Chemical Science}, volume = {118}, number = {3}, year = {2006}, month = {MAY}, pages = {261-267}, publisher = {INDIAN ACADEMY SCIENCES}, type = {Article}, address = {C V RAMAN AVENUE, SADASHIVANAGAR, P B \#8005, BANGALORE 560 080, INDIA}, abstract = {

Influence of the presence Of CO2, which is a mild oxidant, on the performance of the thermal cracking of ethane to ethylene in the absence or presence of limited O-2 at different temperatures (750-900 degrees C), space velocities (1500-9000 h(-1)) and CO2/C2H6 and O-2/C2H6 mole ratios (0-2.0 and 0-0.3 respectively) has been investigated. In both the presence and absence of limited 02, ethane conversion increases markedly because of the presence Of CO2, indicating its beneficial effect on the ethane to ethylene cracking. The increased ethane conversion is, however, not due to the oxidation of ethane to ethylene by CO2; the formation of carbon monoxide in the presence Of CO2 is found to be very small. It is most probably due to the activation of ethane in the presence Of CO2.

}, keywords = {ethane, ethane cracking in presence Of CO2, ethane cracking in presence of CO2 and limited O-2, Ethylene, thermal cracking of ethane}, issn = {0253-4134}, doi = {10.1007/BF02708286}, author = {Choudhary, Vasant R. and Mondal, Kartick C. and Mulla, Shafeek Abdul Rashid} } @article { ISI:000240615500001, title = {Oxy-CO2 reforming of methane to syngas over CoOx/CeO2/SA-5205 catalyst}, journal = {Energy \& Fuel}, volume = {20}, number = {5}, year = {2006}, month = {SEP}, pages = {1753-1756}, publisher = {AMER CHEMICAL SOC}, type = {Article}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

The oxy-CO2 methane reforming (OCRM) process has been investigated over the CoOx/CeO2/SA-5205 catalyst at varying reaction temperatures (750-900 degrees C), O-2/CH4 ratios (0.3- 0.45), and space velocities (20 000 - 100 000 cm(3)/g/h). With an increasing OCRM reaction temperature, the contribution from the CO2 methane reforming reaction increased while that from methane combustion reactions decreased. Correspondingly, there was an increase in the H-2/CO ratio and a sharp decrease in reaction exothermicity. At 900 C (gas hourly space velocity = 46 000 cm(3)/g/h and O-2/CH4 = 0.4), the OCRM reaction over the CoOx/CeO2/SA-5205 catalyst was mildly endothermic with \> 90\% CH4 conversion, \> 95\% H-2 selectivity, and a H-2/CO ratio of 1.63. CH4 conversion was relatively unaffected by the O-2/CH4 ratio used in the OCRM reaction; however, CO2 conversion decreased on increasing the O-2/CH4 ratio. While H-2 selectivity was not significantly affected by the O-2/CH4 ratio, the H-2/CO ratio increased linearly with an increasing O-2/CH4 ratio. The endothermicity of the reaction was found to decrease with an increasing CH4/O-2 ratio, which can be explained on the basis of increased contribution from the methane partial oxidation reaction with an increasing O-2/CH4 ratio.

}, issn = {0887-0624}, doi = {10.1021/ef060138o}, author = {Choudhary, Vasant R. and Mondal, Kartick C. and Choudhary, Tushar V.} } @article { ISI:000241929400015, title = {Oxy-CO2 reforming of methane to syngas over CoOx/MgO/SA-5205 catalyst}, journal = {Fuel}, volume = {85}, number = {17-18}, year = {2006}, month = {DEC}, pages = {2484-2488}, publisher = {ELSEVIER SCI LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND}, abstract = {

The OXY-CO2 methane reforming reaction (OCRM) has been investigated over CoOx supported on a MgO precoated highly macroporous silica-alumina catalyst carrier (SA-5205) at different reaction temperatures (700-900 degrees C), O-2/CH4 ratios (0.3-0.45) and space velocites (20,000-100,000cc/g/h). The reaction temperature had a profound influence on the OCRM performance over the CoO/MgO/SA-5205 catalyst; the methane conversion, CO2 conversion and H-2 selectivity increased while the H-2/CO ratio decreased markedly with increasing reaction temperature. While the O-2/CH4 ratio did not strongly affect the CH4 and CO2 conversion and H-2 selectivity, it had an intense influence on the H-2/CO ratio. The CH4 and CO2 conversion and the H-2 selectivity decreased while the H-2/CO increased with increasing space velocity. The O-2/CH4 ratio and the reaction temperature could be used to manipulate the heat of the reaction for the OCRM process. Depending on the O-2/CH4 ratio and temperature the OCRM process could be operated in a mildly exothermic, thermal neutral or mildly endothermic mode. The OCRM reaction became almost thermoneutral at an OCRM reaction temperature of 850 degrees C, O-2/CH4 ratio of 0.45 and space velocity of 46,000 cc/g/h. The CH4 conversion and H-2 selectivity over the CoO/MgO/SA-5205 catalyst corresponding to thermoneutral conditions were excellent: 95\% and 97\%, respectively with a H-2/CO ratio of 1.8. (c) 2006 Elsevier Ltd. All rights reserved.

}, keywords = {methane, oxy-CO2 reforming, Syngas}, issn = {0016-2361}, doi = {10.1016/j.fuel.2006.04.013}, author = {Choudhary, Vasant R. and Mondal, Kartick C. and Choudhary, Tushar V.} } @article { ISI:000238056800007, title = {Partial oxidation of methane to syngas with or without simultaneous steam or CO2 reforming over a high-temperature stable-NiCoMgCeOx supported on zirconia-hafnia catalyst}, journal = {Applied Catalysis A-General}, volume = {306}, year = {2006}, month = {JUN}, pages = {45-50}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

A NiCoMgCeOx (Ni/Co/Mg/Ce: 1:0.2:1.2:1.2)/zirconia-hafnia catalyst with unusually high thermal stability has been investigated for syngas generation via a process that includes the catalytic partial oxidation of methane (CPOM), the oxidative steam reforming of methane (OSRM) and the oxidative CO2 reforming of methane (OCRM). The catalyst calcined at 1400 degrees C (for 4 h) showed excellent activity/selectivity for the CPOM, OSRM and the OCRM reactions; furthermore no catalyst deactivation was observed for a period of 20 h. For the CPOM process, the selectivity for H-2 was \> 95\% at reaction temperatures \> 650 degrees C however temperatures above 800 degrees C were required to achieve \> 95\% CO selectivity. While the reaction temperature had a considerable influence on the CPOM product H-2/CO ratio, the space velocity (at 850 degrees C) did not affect it to any significant extent. For the OSRM process, the H2O/CH4 ratio and the reaction temperature had a strong effect on the product H-2/CO ratio and the heat of the reaction; depending on the H2O/CH4 ratio and reaction temperature, the OSRM process could be operated in a mildly exothermic, thermoneutral or mildly endothermic mode. The CO2 conversion was very strongly affected by the reaction temperature in the OCRM process; reasonably high CO2 conversion ( \> 40\%) could only be obtained at high OCRM reaction temperatures ( \> 850 degrees C). The exothermicity of the OCRM reaction was found to decrease with increasing reaction temperature. (c) 2006 Elsevier B.V. All rights reserved.

}, keywords = {dry (CO2) reforming, high-temperature stable, methane, oxy-steam reforming, Partial oxidation, Steam reforming, Syngas}, issn = {0926-860X}, doi = {10.1016/j.apcata.2006.03.032}, author = {Choudhary, Vasant R. and Mondal, Kartick C. and Choudhary, Tushar V.} } @article {sanjayan, title = {CO2 reforming of methane to syngas over highly active and stable supported CoOx (accompanied with MgO, ZrO2 or CeO2) catalysts}, journal = {Applied Catalysis A-General}, volume = {316}, number = {1}, year = {2007}, month = {JAN}, pages = {47-52}, publisher = {GEORG THIEME VERLAG KG}, type = {Article}, address = {RUDIGERSTR 14, D-70469 STUTTGART, GERMANY}, abstract = {

{Catalytically inactive CoOx-MgO (calcined at 900 degrees C) becomes highly active and selective in the CO2 reforming of methane to syngas when it is deposited on a commercial low surface-area macro-porous silica-alumina support (SA-5205) or when CoOx is deposited on the support precoated with MgO. Both the supported CoOx and MgO containing catalysts (CoOx -MgO/SA-5205 and CoOx/MgO/SA-5205) show high methane conversion (\> 98\%) activity and H-2 selectivity (\> 94\%) and also high stability against carbon deposition [

}, keywords = {arylboronic acids, diarylmethylidenefluorene, dibromomethylidenefluorene, Pd-mediated coupling, Suzuki reaction}, issn = {0936-5214}, doi = { 10.1016/j.apcata.2006.09.016}, author = {Mondal, Kartick C. and Choudhary, Vasant R. and Joshi, Upendra A.} } @article { ISI:000243163000068, title = {Oxy-methane reforming over high temperature stable NiCoMgCeOx and NiCoMgOx supported on zirconia-haffnia catalysts: accelerated sulfur deactivation and regeneration}, journal = {Catalysis Communications}, volume = {8}, number = {3}, year = {2007}, month = {MAR}, pages = {561-564}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

NiCoMgOx and NiCoMgCeOx on commercial low surface area zirconia-haffnia catalysts have unusually high thermal stability (\>= 2000 degrees C) for syngas generation via the methane partial oxidation process (J. Catal., 233, 36, 2005). Herein we report the results on accelerated sulfur deactivation (0.74 mol\% sulfur in feed) and corresponding regeneration (at 800 degrees C in 1:1 O-2 + N-2 flow) over these catalysts. The NiCoMgCeOx catalyst, due to a larger mobility of lattice oxygen, showed a considerably higher resistance to sulfur poisoning; the higher mobility of the lattice oxygen in case of the NiCoMgCeOx catalyst may be related to the presence of CeO2. During the deactivation process, the selectivity for H-2 was decreased to a much greater extent than that for CO. Regeneration studies showed that even after complete deactivation of the catalysts, the original activity/selectivity of both the catalysts could be completely restored after a simple regeneration process. Based on their exceptionally high thermal stability, high activity/selectivity and easily regenerability, the NiCoMOx, and NiCoMgCeOx catalysts appear to be very promising candidates for the CPOM process. (c) 2006 Elsevier B.V. All rights reserved.

}, keywords = {Deactivation, high temperature stable, methane, Partial oxidation, Regeneration, Sulfur}, issn = {1566-7367}, doi = {10.1016/j.catcom.2006.08.007}, author = {Choudhary, Vasant R. and Mondal, Kartick C. and Choudhary, Tushar V.} }