Trionfetti, Cristiano, Babich, Igor V., Seshan, K., Lefferts, Leon
The surface morphology of Li-promoted MgO catalysts prepared using the sol−gel method (sg) and wet impregnation procedure (imp), respectively, has been studied by low-temperature infrared...
Agiral, A., Groenland, A.W., Kumar Chinthaginjala, J., Seshan, K., Lefferts, L., Gardeniers, J.G.E.
Carbon nanofibres (CNFs) and tungsten oxide (W18O49) nanowires have been incorporated into a continuous flow type microplasma reactor to increase the reactivity and efficiency of the barrier...
Preparation of well-dispersed Pt/SiO2 catalysts using low-temperature treatments. (2006)
Radivojevic, D., Seshan, K., Lefferts, L.
This work explores methods to prepare platinum on silica catalyst using temperatures as low as possible. Therefore, thermal stability in both oxidizing and reducing atmosphere of eight different...
Catalyst deactivation during steam reforming of acetic acid over Pt/ZrO2 (2006)
Takanabe, Kazuhiro, Aika, Ken-ichi, Seshan, K., Lefferts, L.
Steam reforming of acetic acid as a model compound present in bio-oil over Pt/ZrO2 catalysts has been investigated. Pt/ZrO2 yields steam reforming products (i.e., H2, CO, CO2) to the amounts...
Propane conversion in a surface-discharge microplasma reactor (2006)
Agiral, A., Trionfetti, C., Seshan, K., Lefferts, L., Gardeniers, J.G.E.
Non-conventional oxidation catalysis (2005)
Lefferts, Leon, Seshan, K., Mojet, Barbara L., Ommen Van, Jan
This short review provides an overview as well as background of ongoing work in our laboratory on unconventional catalysts in selective oxidation reactions with remarkable selectivity. The three...
Babich, I.V., Seshan, K., Lefferts, L.
NOx emission during the regeneration of coked fluid catalytic cracking (FCC) catalysts is an environmental problem. In order to follow the route to NOx formation and try to find ways to suppress it,...
Selective removal of NO2 in the presence of oxygen and NO over Pd/SiO2 catalysts (2004)
Li, Mingshi, Seshan, K., Lefferts, Leon
Catalytic reduction of NO2 in the presence of excess oxygen and NO has been studied over a 0.2% Pd/SiO2 catalyst between 120 and 260 °C. CO is effective in selective reduction of NO2 at temperatures...
Sustainable hydrogen from bio-oil - Steam reforming of acetic acid as a model oxygenate (2004)
Takanabe, Kazuhiro, Aika, Ken-ichi, Seshan, K., Lefferts, Leon
Steam reforming of acetic acid over Pt/ZrO2 catalysts has been investigated. Pt/ZrO2 catalysts are very active, completely converting acetic acid, and give a hydrogen yield close to thermodynamic...
Transitiepad "Bioraffinage" (2003)
Elbersen, H.W., Sanders, J.P.M., Goetheer, E., Boerrigter, H., ...
Maisuls, S.E., Lefferts, L., Seshan, K., Furusawa, T., Aika, K., Mosqueda Jimenez, B., ...
Kinetic and in situ spectroscopic studies of Co¿Pt/MFI and Co¿Pt/HY catalysts for the selective reduction of NOx with propylene in the presence of oxygen were carried out. The results of catalytic...
Leveles, L., Seshan, K., Lercher, J.A., Lefferts, L.
Activation of propane over Li/MgO catalyst has been investigated. It is shown that a small fraction of the oxygen ions in Li/MgO catalysts can be removed from the catalyst by reduction treatment in...
Leveles, L., Seshan, K., Lercher, J.A., Lefferts, L.
Oxidative conversion of lower alkanes over lithium-promoted magnesia catalysts offers a viable alternative for propene and ethene production. The catalytic performance of propane oxidative...
Selective reduction of NO to N2 in the presence of oxygen over supported silver catalysts (2002)
Furusawa, T., Seshan, K., Lercher, J.A., Lefferts, L., Aika, K.
Meunier, F.C., Domokos, L., Seshan, K., Lercher, J.A.
The sorption and reaction of but-1-ene over a ferrierite sample was studied by in situ IR spectroscopy to relate the selectivity to isobutene and the sorbed species. The spectra highlighted the...
Selective reduction of NO to nitrogen in the presence of oxygen (2001)
Furusawa, T., Seshan, K., Maisuls, S.E., Lercher, J.A., Lefferts, L., Aika, K.
Applied molecular simulations over FER-, TON- and AEL-type zeolites (2001)
Domokos, L., Lefferts, L., Seshan, K., Lercher, J.A.
Interaction and transport of representative (un)saturated hydrocarbon molecules involved in the proposed reaction network of n-butene isomerization in zeolites FER, TON, and AEL have been studied by...
Oxidative dehydrogenation and cracking of ethane and propane over LiDy Mg mixed oxides (2001)
Fuchs, Stefan, Leveles, L., Seshan, K., Lefferts, Leon, Lemonidou, Angeliki, Lercher, Johannes A.
The oxidative dehydrogenation and cracking of ethane and propane over LiDyMg mixed oxides is reported. High yields of olefins and only moderate formation of carbon oxides was observed. Both are...
Domokos, L., Lefferts, L., Seshan, K., Lercher, J.A.
Transformation of linear butenes and iso-butene was carried out over H-FER (Si/Al ratio of 8) in a wide temperature and pressure range and with varying contact times. Catalyst lifetime over 100 h...
The importance of acid site locations for n-butene skeletal isomerization on ferrierite (2000)
Domokos, L., Lefferts, L., Seshan, K., Lercher, J.A.
The role of the previous termacid site locationnext term in H-ferrierite (H-FER) on the skeletal isomerization of linear butenes was studied. Assignment of OH groups observed in FTIR analysis is...
Deactivation and Coke Accumulation during CO2/CH4 Reforming over Pt Catalysts (1998)
Bitter, J.H., Seshan, K., Lercher, J.A.
The Deactivation of Pt catalysts used in the generation of synthesis gas via CO2/CH4 reforming depends strongly on the support and the metalparticle size. Methods of Physicochemical characterization...
Design of Stable Catalysts for Methane-Carbon Dioxide Reforming (1998)
Seshan, K., Bitter, J.H., Lercher, J.A.
PtZrO2 is an active and stable catalyst for methane- carbon dioxide reforming reaction. The reaction between CO2 and CH4 to yield synthesis gas might proceed vie two different pethways. At high...
Mono and bifunctional pathways of CO2/CH4 reforming over Pt and Rh based catalysts (1997)
Bitter, J.H., Seshan, K., Lercher, J.A.
Despite the high thermodynamic driving force to form coke under the reaction conditions applied Pt/ZrO2 and Rh supported on y-Al2O3 and ZrO2 are active and stable catalysts for CO2/CH4 reforming....
The state of Zirconia Suported Platinum Catalysts for CO2/CH4 Reforming (1997)
Bitter, J.H., Seshan, K., Lercher, J.A.
In Pt/ZrO2 catalysts used for CO2/CH4 reforming to syngas, not all accessible Pt contributes equally to the activity of the catalyst. The cataalytic activity is determined by the accessibility of Pt...
TAP investigations of the CO2 reforming of CH4 over Pt/ZrO2 (1997)
The adsorption and reaction characteristics of methane, carbon dioxide, carbon monoxide, and hydrogen have been investigated over a ZrO2support and a Pt/ZrO2catalyst by using a temporal analysis of...
Sorption and activation of hydrocarbons by molecular sieves (1997)
Substantial progress has been made recently in the understanding of sorption and activation of alkanes. This progress reflects the emergence of new theoretical and experimental results, leading to a...
Improving the stability of H-mordenite for n-butane isomerization (1997)
Asuquo, R.A., Mirth, G.C., Seshan, K., Pieterse, J.A.Z., Lercher, J.A.
The conversion ofn-butane over mordenite-based catalysts in the presence of hydrogen and water was investigated for reaction temperatures between 523 and 623 K. Special attention was given to the...
The state of zirconia supported platinum catalysts for CO2/CH4 reforming (1997)
Bitter, J.H., Seshan, K., Lercher, J.A.
In Pt/ZrO2catalysts used for CO2/CH4reforming to syngas, not all accessible Pt contributes equally to the activity of the catalyst. The catalytic activity is determined by the accessibilityof Pt on...
Dehydrogenation of light alkanes over zeolites (1997)
Narbeshuber, T., Brait, A., Seshan, K., Lercher, J.A.
The conversion of light paraffins to olefins and the secondary reactions of the unsaturated compounds were investigated on H-ZSM5 and H-Y zeolites between 733 and 823 K. Steady state- and transient...
Bitter, J.H., Hally, W., Seshan, K., Ommen, J.G. Van, Lercher, J.A.
Pt supported on y-Al2O3, TiO2 and ZrO2 are active catalysts for the CO2 reforming of methane to synthesis gas. The stability of the catalysts increased in the order Pt / y-Al2O3 < Pt / TiO2 < Pt /...
Design of stable catalysts for methane-carbon dioxide reforming (1996)
Lercher, J.A., Bitter, J.H., Hally, W., Niessen, W., Seshan, K.
The activity and stability of catalysts for methane-carbon dioxide reforming depend subtly upon the support and the active metal. Methane decomposes to carbon and hydrogen, forming carbon on the...
Xue, E., Seshan, K., Ross, J.R.H.
Three types of platinum catalysts, Pt/SiO2, Pt/¿-Al2O3 and Pt/ZrO2 were examined for the oxidation of NO to NO2 of SO2 to SO3. The activity order for both oxidation reactions was found to be:...
Bitter, J.H., Hally, W., Seshan, K., Ommen Van, J.G., Lercher, J.A.
Pt supported on ¿-Al2O3, TiO2 and ZrO2 are active catalysts for the CO2 reforming of methane to synthesis gas. The stability of the catalysts increased in the order Pt/¿-A12O3 < Pt/TiO2 < Pt/ZrO2....
Hydrogen/Deuterium Exchange duringn-Butane Conversion on H-ZSM-5 (1996)
Narbeshuber, T., Stockenhuber, M., Brait, A., Seshan, K., Lercher, J.A.
Steady-state isotope tracer studies and isotope transient response experiments ofn-butane conversion on H-ZSM-5 (Si/Al = 35) were carried out between 673 and 823 K. Among the three main reactions,...
Oxidative dehydrogenation of propane over niobia supported vanadium oxide catalysts (1996)
Watling, T.C., Deo, G., Seshan, K., Wachs, I.E., Lercher, J.A.
Oxidative dehydrogenation (ODH) of propane is examined over a series of catalysts, which include Nb2O5 supported monolayer V2O5 catalysts, bulk vanadia-niobia with different vanadium oxide loadings...
The catalytic conversion of natural gas to useful products (1996)
Ross, J.R.H., Hegarty, M.E.S., Seshan, K.
This paper gives a brief summary of some processes, direct and indirect, for the conversion of natural gas to useful products. It then proceeds to give an outline of some work from the authors'...
The influence of extraframework aluminum on H-FAU catalyzed cracking of light alkanes (1996)
Narbeshuber, T., Brait, A., Seshan, K., Lercher, J.A.
The conversion of light linear and branched alkanes on two faujasite samples containing different concentrations of free Brønsted acid sites and extraframework alumina (EFAL) was studied between 733...
Smits, R.H.H., Seshan, K., Ross, J.R.H., Anantharaman, M.R., ...
A series of vanadium-niobium oxide catalysts in which the vanadia content varies between 0.3 and 18 mol% was prepared by coprecipitation. These catalysts were characterized by X-ray diffraction...
Investigation of V2O5/Nb2O5 Catalysts by 51V Solid-State NMR (1995)
Smits, R.H.H., Seshan, K., Ross, J.R.H.
Vanadium-niobium oxide catalysts containing variable amounts of vanadium and prepared by coprecipitation were investigated using 51V solid-state NMR. It was found that, in samples containing less...
Problem of coke formation on Ni/ZrO2 catalysts during the carbon dioxide reforming of methane (1994)
Hally, W., Bitter, J.H., Seshan, K., Lercher, J.A., Ross, J.R.H.
The suitability of zirconia-based nickel catalysts for the CO2 reforming reaction has been investigated with emphasis on the stability of the cattalysts under conditions favourable towards carbon...
Oxidative coupling of methane over doped Li/MgO catalysts (1994)
Hoogendam, G.C., Seshan, K., Ommen Van, J.G., Ross, J.R.H.
A series of zirconia doped Li/MgO catalysts with a fixed amount of zirconia and varying concentrations of lithium was used for the oxidative coupling of methane. It was found that an increase in...
Swaan, H.M., Li, X., Seshan, K., Ommen Van, J.G., Ross, J.R.H.
The promoting effect of niobium in a Li/MgO catalyst for the oxidative coupling of methane (OCM) and for the oxidative dehydrogenation of ethane (ODHE) has been studied in some detail. It has been...
Smits, R.H.H., Seshan, K., Leemreize, H., Ross, J.R.H.
The influence of various preparation methods on the performance of V-Nb-0 catalysts has been investigated. It was found that the activity and selectivity of a vanadium site depend on the nature of...
Xue, E., Seshan, K., Ommen Van, J.G., Ross, J.R.H.
The catalytic oxidation of nitric oxide to nitrogen dioxide in the presence of sulphur dioxide over a standard Pt/SiO2 catalyst (EuroPt-1) was studied. The gas-phase reactions between nitric oxide,...
The use of niobia in oxidation catalysis (1993)
Ross, J.R.H., Smits, R.H.H., Seshan, K.
This paper summarises the background to work carried out at the University of Twente on the use of niobia as a catalyst for the oxidative dehydrogenation of propane to propylene and discusses the...
Swaan, H.M., Toebes, A., Seshan, K., Ommen Van, J.G., Ross, J.R.H.
The oxidative dehydrogenation of ethane was studied with the use of promoted Li/MgO catalysts at temperatures of 600¿650°C. The addition of known promoters, cobalt and tin, gave a slight Increase...
Swaan, H.M., Toebes, A., Ommen Van, J.G., Seshan, K., Ross, J.R.H.
Kinetic and mechanistic aspects of the oxidative dehydrogenation of ethane catalysed by Li/MgO and Li/Na/MgO have been investigated. Initial rate measurements at 600°C; revealed that the Li/MgO...
Kruidhof, H., Seshan, K., Vries De, K.J., Burggraaf, A.J.
Coprecipitation as a method of preparation for bismuth oxides based ceramics yields relatively strong and machineable materials in comparison with the solid state reaction. Compositions within the...
Kruidhof, H., Seshan, K., Lippens Jr., B.C., Gellings, P.J., Burggraaf, A.J.
A study of the preparative variables in the synthesis of ceramics based on Bi2O3-Er2O3 solid solutions has shown that the best results are obtained with a coprecipitation method. Critical parameters...
Vermicular graphite cast iron current state of the art (1985)
Murthy, VSR, Seshan, S, Seshan, K
Vermicular graphite cast iron is a new addition to the family of cast irons. Various methods for producing vermicular graphite cast iron are briefly discussed in this paper. The mechanical and...
On the dissociation of hexagonal interstitial frank loops (1976)
Seshan, K., Gaboriaud, R.J., Boisson, M., Grilhé, J.
Some preliminary results of equilibrium energy computations of dissociated interstitial Frank loops are presented. It is argued that interstitial defects could dissociate into acute or obtuse angle...