Gérard Delahay - Academia.edu (original) (raw)

Papers by Gérard Delahay

Research paper thumbnail of Light hydrocarbons ammoxidation into acetonitrile over Mo–ZSM-5 catalysts: Effect of molybdenum precursor

Microporous and Mesoporous Materials, 2016

Research paper thumbnail of Effect of the chromium precursor nature on the physicochemical and catalytic properties of Cr-ZSM-5 catalysts: Application to the ammoxidation of ethylene

Journal of Molecular …, Jan 1, 2011

Research paper thumbnail of Sol�gel derived mesoporous Cr/Al 2 O 3 catalysts for SCR of NO by ammonia

Research paper thumbnail of Solid–State Ion Exchange of Molybdenum ( VI ) Acetylacetonate into ZSM-5 Zeolite

Research paper thumbnail of Selective catalytic reduction of NOx by NH3 on V-Mo-zeolite prepared by solid-state ion exchange method

Studies in Surface Science and Catalysis, 2008

V-Mo-Zeolite catalysts prepared by solid-state ion exchange were studied in the selective catalyt... more V-Mo-Zeolite catalysts prepared by solid-state ion exchange were studied in the selective catalytic reduction of NOx by ammonia. The catalysts were characterized by chemical analysis, X-ray powder diffraction, N2 adsorption (BET), DRIFT, UV-Vis and Raman, spectroscopy and H2 TPR. Catalytic results show that upon addition of Mo to V-ZSM-5, catalytic performance was enhanced compared to V-ZSM-5.

Research paper thumbnail of Sol–gel derived mesoporous Cr/Al2O3 catalysts for SCR of NO by ammonia

Journal of Porous Materials, 2010

Catalytic performances of Cr/Al2O3 catalysts were investigated in Selective Catalytic Reduction (... more Catalytic performances of Cr/Al2O3 catalysts were investigated in Selective Catalytic Reduction (SCR) of NO by NH3 in the presence of oxygen. Solids were prepared either by sol–gel method or by impregnation and were characterized by different techniques such as chemical analysis, N2 physisorption, XRD, 27Al MAS NMR, DRIFT, UV–Vis Diffuse Reflectance (DRS), Raman Spectroscopy and Temperature Programmed Reduction by H2

Research paper thumbnail of Influence of the V+Mo/Al ratio on vanadium and molybdenum speciation and catalytic properties of V–Mo–ZSM-5 prepared by solid-state reaction

Research paper thumbnail of Selective catalytic reduction of NO with NH3 over HZSM-5-supported fe-cu nanocomposite catalysts: The fe-cu bimetallic effect

Research paper thumbnail of Ammoxidation of ethylene to acetonitrile over Cr-ZSM-5 catalysts

Studies in Surface Science …, Jan 1, 2008

Research paper thumbnail of Cr-ZSM-5 catalysts for ethylene ammoxidation: Effects of precursor nature and Cr/Al molar ratio on the physicochemical and catalytic properties

Microporous and Mesoporous Materials, 2013

Research paper thumbnail of Selective catalytic reduction of NOx by NH 3 on V-Mo-zeolite prepared by solid-state ion exchange method

Studies in Surface Science and Catalysis, 2008

V-Mo-Zeolite catalysts prepared by solid-state ion exchange were studied in the selective catalyt... more V-Mo-Zeolite catalysts prepared by solid-state ion exchange were studied in the selective catalytic reduction of NOx by ammonia. The catalysts were characterized by chemical analysis, X-ray powder diffraction, N2 adsorption (BET), DRIFT, UV-Vis and Raman, spectroscopy and H2 TPR. Catalytic results show that upon addition of Mo to V-ZSM-5, catalytic performance was enhanced compared to V-ZSM-5.

Research paper thumbnail of Selective catalytic reduction of nitric oxide with ammonia on copper (II) ion-exchanged offretite

Catalysis Communications, 2005

Copper K-offretite catalysts prepared by ion exchange were characterized by XRD, H2-TPR and evalu... more Copper K-offretite catalysts prepared by ion exchange were characterized by XRD, H2-TPR and evaluated in the selective catalytic reduction of NO (NO-SCR) by ammonia. Despite several successive exchanges, the quantity of copper introduced remains low and the exchange ratio does not exceed 50%. The NO conversion profiles have a sigmoid curve shape. Full NO conversion in N2 is reached above

Research paper thumbnail of Recent Advances in Cu I/II Y: Experiments and Modeling

Catalysis Reviews-science and Engineering, 2006

An overview of the CuY material is performed on the basis of the results obtained during the last... more An overview of the CuY material is performed on the basis of the results obtained during the last 5 years on their structure (nature of the Cu species, siting, coordination …), their use and reactivity, based on TPR, XRD and various ex situ and in situ spectroscopies such as XAS, IR and EPR. A brief summary of previous work is

Research paper thumbnail of N 2O decomposition in the presence of ammonia on faujasite-supported metal catalysts

Applied Catalysis B-environmental, 1999

The reduction of N2O to N2 was carried out by temperature programmed surface reaction (TPSR) from... more The reduction of N2O to N2 was carried out by temperature programmed surface reaction (TPSR) from 473 to 873K in He, He+3% O2, He+0.02% NH3 and He+3% O2+0.02% NH3 on H–FAU supported transition metal catalysts. In the absence of oxygen, the addition of NH3 considerably shifts the N2O conversion profile towards lower temperatures. This is particularly true for the Ru–

Research paper thumbnail of EPR Investigation of Fe-Exchanged Beta-Zeolites

Research paper thumbnail of Selective catalytic reduction of NO by NH3 on Cu-faujasite catalysts: an experimental and quantum chemical approach

Chemphyschem : a European journal of chemical physics and physical chemistry, Jan 16, 2002

The selective catalytic reduction (SCR) of NO by NH3 in the presence of O2 on Cu-faujasite (Cu-FA... more The selective catalytic reduction (SCR) of NO by NH3 in the presence of O2 on Cu-faujasite (Cu-FAU) has been studied. Substitution of some Cu2+ with H+ and Na+ cations, compensating for the negative charge of the zeolite framework, forms the various CuHNa-FAU studied. The amount of Cu was held constant and the proportion of H+ and Na+ varied in the sample. The substitution of Na+ for H+ increases sharply the SCR rate by lowering the temperature of reaction by about 150 K. It is proposed that the rate increase mainly comes from an unhindered migration of Cu from hidden to active sites and a modification of the redox properties of Cu species. The former was demonstrated by diffuse reflectance IR spectroscopy of adsorbed CO. The change in redox properties was demonstrated by a faster oxidation of Cu+ to Cu2+ (rate-determining step). Quantum chemical calculations on model clusters of CuHNa-FAU indicate that the faster rate of oxidation can be explained by a higher lability of protons in...

Research paper thumbnail of Influence of co-cations in the selective catalytic reduction of NO by NH3 over copper exchanged faujasite zeolites

Research paper thumbnail of Influence of the preparation method on the properties of Fe-ZSM-5 for the selective catalytic reduction of NO by n-decane

Research paper thumbnail of The simultaneous catalytic reduction of NO and N 2O by NH 3 using an Fe-zeolite-beta catalyst

Applied Catalysis B-environmental, 2000

An Fe-Zeolite-beta (Fe-BEA) catalyst, composed only of Fe cations or oxocations in charge compens... more An Fe-Zeolite-beta (Fe-BEA) catalyst, composed only of Fe cations or oxocations in charge compensation sites of the zeolite, is active in the simultaneous removal of NO (1500ppm) and N2O (1000ppm) by NH3 (2500ppm) in the presence of O2 (3vol.%). In temperature-programmed surface reaction (TPSR) experiments (ramp: 10Kmin−1 from 423 to 823K, space velocity: 200,000h−1), the light-off temperature, at 50% conversion,

Research paper thumbnail of Selective Catalytic Reduction of Nitrous Oxide by Ammonia on Iron Zeolite Beta Catalysts in an Oxygen Rich Atmosphere: Effect of Iron Contents

Journal of Catalysis, 2001

A series of iron-exchanged zeolite beta (BEA) has been characterized by temperature programmed de... more A series of iron-exchanged zeolite beta (BEA) has been characterized by temperature programmed desorption (TPD) of oxygen and tested in the catalytic reduction of N2O by NH3. TPD of O2 has clearly shown that iron-oxo species formed upon reoxidation by nitrous oxide of Fe2+-BEA are more labile than those generated by calcination in air. In the selective catalytic reduction of

Research paper thumbnail of Light hydrocarbons ammoxidation into acetonitrile over Mo–ZSM-5 catalysts: Effect of molybdenum precursor

Microporous and Mesoporous Materials, 2016

Research paper thumbnail of Effect of the chromium precursor nature on the physicochemical and catalytic properties of Cr-ZSM-5 catalysts: Application to the ammoxidation of ethylene

Journal of Molecular …, Jan 1, 2011

Research paper thumbnail of Sol�gel derived mesoporous Cr/Al 2 O 3 catalysts for SCR of NO by ammonia

Research paper thumbnail of Solid–State Ion Exchange of Molybdenum ( VI ) Acetylacetonate into ZSM-5 Zeolite

Research paper thumbnail of Selective catalytic reduction of NOx by NH3 on V-Mo-zeolite prepared by solid-state ion exchange method

Studies in Surface Science and Catalysis, 2008

V-Mo-Zeolite catalysts prepared by solid-state ion exchange were studied in the selective catalyt... more V-Mo-Zeolite catalysts prepared by solid-state ion exchange were studied in the selective catalytic reduction of NOx by ammonia. The catalysts were characterized by chemical analysis, X-ray powder diffraction, N2 adsorption (BET), DRIFT, UV-Vis and Raman, spectroscopy and H2 TPR. Catalytic results show that upon addition of Mo to V-ZSM-5, catalytic performance was enhanced compared to V-ZSM-5.

Research paper thumbnail of Sol–gel derived mesoporous Cr/Al2O3 catalysts for SCR of NO by ammonia

Journal of Porous Materials, 2010

Catalytic performances of Cr/Al2O3 catalysts were investigated in Selective Catalytic Reduction (... more Catalytic performances of Cr/Al2O3 catalysts were investigated in Selective Catalytic Reduction (SCR) of NO by NH3 in the presence of oxygen. Solids were prepared either by sol–gel method or by impregnation and were characterized by different techniques such as chemical analysis, N2 physisorption, XRD, 27Al MAS NMR, DRIFT, UV–Vis Diffuse Reflectance (DRS), Raman Spectroscopy and Temperature Programmed Reduction by H2

Research paper thumbnail of Influence of the V+Mo/Al ratio on vanadium and molybdenum speciation and catalytic properties of V–Mo–ZSM-5 prepared by solid-state reaction

Research paper thumbnail of Selective catalytic reduction of NO with NH3 over HZSM-5-supported fe-cu nanocomposite catalysts: The fe-cu bimetallic effect

Research paper thumbnail of Ammoxidation of ethylene to acetonitrile over Cr-ZSM-5 catalysts

Studies in Surface Science …, Jan 1, 2008

Research paper thumbnail of Cr-ZSM-5 catalysts for ethylene ammoxidation: Effects of precursor nature and Cr/Al molar ratio on the physicochemical and catalytic properties

Microporous and Mesoporous Materials, 2013

Research paper thumbnail of Selective catalytic reduction of NOx by NH 3 on V-Mo-zeolite prepared by solid-state ion exchange method

Studies in Surface Science and Catalysis, 2008

V-Mo-Zeolite catalysts prepared by solid-state ion exchange were studied in the selective catalyt... more V-Mo-Zeolite catalysts prepared by solid-state ion exchange were studied in the selective catalytic reduction of NOx by ammonia. The catalysts were characterized by chemical analysis, X-ray powder diffraction, N2 adsorption (BET), DRIFT, UV-Vis and Raman, spectroscopy and H2 TPR. Catalytic results show that upon addition of Mo to V-ZSM-5, catalytic performance was enhanced compared to V-ZSM-5.

Research paper thumbnail of Selective catalytic reduction of nitric oxide with ammonia on copper (II) ion-exchanged offretite

Catalysis Communications, 2005

Copper K-offretite catalysts prepared by ion exchange were characterized by XRD, H2-TPR and evalu... more Copper K-offretite catalysts prepared by ion exchange were characterized by XRD, H2-TPR and evaluated in the selective catalytic reduction of NO (NO-SCR) by ammonia. Despite several successive exchanges, the quantity of copper introduced remains low and the exchange ratio does not exceed 50%. The NO conversion profiles have a sigmoid curve shape. Full NO conversion in N2 is reached above

Research paper thumbnail of Recent Advances in Cu I/II Y: Experiments and Modeling

Catalysis Reviews-science and Engineering, 2006

An overview of the CuY material is performed on the basis of the results obtained during the last... more An overview of the CuY material is performed on the basis of the results obtained during the last 5 years on their structure (nature of the Cu species, siting, coordination …), their use and reactivity, based on TPR, XRD and various ex situ and in situ spectroscopies such as XAS, IR and EPR. A brief summary of previous work is

Research paper thumbnail of N 2O decomposition in the presence of ammonia on faujasite-supported metal catalysts

Applied Catalysis B-environmental, 1999

The reduction of N2O to N2 was carried out by temperature programmed surface reaction (TPSR) from... more The reduction of N2O to N2 was carried out by temperature programmed surface reaction (TPSR) from 473 to 873K in He, He+3% O2, He+0.02% NH3 and He+3% O2+0.02% NH3 on H–FAU supported transition metal catalysts. In the absence of oxygen, the addition of NH3 considerably shifts the N2O conversion profile towards lower temperatures. This is particularly true for the Ru–

Research paper thumbnail of EPR Investigation of Fe-Exchanged Beta-Zeolites

Research paper thumbnail of Selective catalytic reduction of NO by NH3 on Cu-faujasite catalysts: an experimental and quantum chemical approach

Chemphyschem : a European journal of chemical physics and physical chemistry, Jan 16, 2002

The selective catalytic reduction (SCR) of NO by NH3 in the presence of O2 on Cu-faujasite (Cu-FA... more The selective catalytic reduction (SCR) of NO by NH3 in the presence of O2 on Cu-faujasite (Cu-FAU) has been studied. Substitution of some Cu2+ with H+ and Na+ cations, compensating for the negative charge of the zeolite framework, forms the various CuHNa-FAU studied. The amount of Cu was held constant and the proportion of H+ and Na+ varied in the sample. The substitution of Na+ for H+ increases sharply the SCR rate by lowering the temperature of reaction by about 150 K. It is proposed that the rate increase mainly comes from an unhindered migration of Cu from hidden to active sites and a modification of the redox properties of Cu species. The former was demonstrated by diffuse reflectance IR spectroscopy of adsorbed CO. The change in redox properties was demonstrated by a faster oxidation of Cu+ to Cu2+ (rate-determining step). Quantum chemical calculations on model clusters of CuHNa-FAU indicate that the faster rate of oxidation can be explained by a higher lability of protons in...

Research paper thumbnail of Influence of co-cations in the selective catalytic reduction of NO by NH3 over copper exchanged faujasite zeolites

Research paper thumbnail of Influence of the preparation method on the properties of Fe-ZSM-5 for the selective catalytic reduction of NO by n-decane

Research paper thumbnail of The simultaneous catalytic reduction of NO and N 2O by NH 3 using an Fe-zeolite-beta catalyst

Applied Catalysis B-environmental, 2000

An Fe-Zeolite-beta (Fe-BEA) catalyst, composed only of Fe cations or oxocations in charge compens... more An Fe-Zeolite-beta (Fe-BEA) catalyst, composed only of Fe cations or oxocations in charge compensation sites of the zeolite, is active in the simultaneous removal of NO (1500ppm) and N2O (1000ppm) by NH3 (2500ppm) in the presence of O2 (3vol.%). In temperature-programmed surface reaction (TPSR) experiments (ramp: 10Kmin−1 from 423 to 823K, space velocity: 200,000h−1), the light-off temperature, at 50% conversion,

Research paper thumbnail of Selective Catalytic Reduction of Nitrous Oxide by Ammonia on Iron Zeolite Beta Catalysts in an Oxygen Rich Atmosphere: Effect of Iron Contents

Journal of Catalysis, 2001

A series of iron-exchanged zeolite beta (BEA) has been characterized by temperature programmed de... more A series of iron-exchanged zeolite beta (BEA) has been characterized by temperature programmed desorption (TPD) of oxygen and tested in the catalytic reduction of N2O by NH3. TPD of O2 has clearly shown that iron-oxo species formed upon reoxidation by nitrous oxide of Fe2+-BEA are more labile than those generated by calcination in air. In the selective catalytic reduction of