01805nas a2200265 4500008004100000022001400041245010700055210006900162260007300231300001000304490000800314520089400322653002901216653000901245653001501254653001701269653000801286100001501294700001601309700001901325700002801344700002301372700002501395856011901420 2010 eng d a1381-116900aNO reduction under diesel exhaust conditions over Au/Al2O3 prepared by deposition-precipitation method0 aNO reduction under diesel exhaust conditions over AuAl2O3 prepar aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcMAY a90-970 v3223 a

Gold supported on alumina was prepared by urea deposition-precipitation method and compared to silver supported on alumina for the selective catalytic reduction of NO by hydrocarbons under lean conditions. The catalyst showed activity in the reduction of NO and 100% selectivity towards N-2 in the temperature range 300-350 degrees C. At higher temperature the NO conversion decreased due to competitive oxidative reactions of the reductants. XPS analysis confirmed the good stability of gold nanoparticles deposited on alumina. Infrared studies showed the formation of various adsorbed species (formates, carboxylates, ad-NOx and cyanide) on the catalyst surface. Addition of H-2 to the feed containing decane enhanced the formation of these species on the catalyst surface as well as the catalytic activity for the NO conversion to N-2. (C) 2010 Elsevier B.V. All rights reserved.

10aDeposition-precipitation10aGold10aIn situ IR10aNO reduction10aXPS1 aMiguel, P.1 aGranger, P.1 aJagtap, Neelam1 aUmbarkar, Shubhangi, B.1 aDongare, Mohan, K.1 aDujardin, Christophe uhttps://library.ncl.res.in/content/no-reduction-under-diesel-exhaust-conditions-over-aual2o3-prepared-deposition-002282nas a2200253 4500008004100000022001400041245012200055210006900177260007100246300001200317490000800329520134200337653003501679653001901714653003401733653002201767653001801789100001601807700001101823700002501834700002301859700001601882856013001898 2011 eng d a0920-586100aCeria-zirconia mixed oxides as thermal resistant catalysts for the decomposition of nitrous oxide at high temperature0 aCeriazirconia mixed oxides as thermal resistant catalysts for th aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbFrench GDFSUEZ CocNOV a453-4570 v1763 a

This present study deals with the development of thermally stable catalysts for the decomposition of nitrous oxide. There is actually a growing interest to minimise the emissions of nitrous oxide (N(2)O) as side-product from nitric acid plants due to a global warming potential of approximately 300 times higher than that of CO(2). Different strategies have already been implemented at industrial scale but they are still suffering from significant drawbacks essentially associated to a poor selectivity and sometimes a short lifetime in particular when the catalytic process is inserted downstream the ammonia burner. In those critical conditions, with high residual temperature of similar to 900 degrees C, significant surface and bulk reconstructions take place and then lead to drastic losses of specific surface area and related catalytic performances in the decomposition of N(2)O to N(2). Previous investigations performed in our laboratory revealed the potentiality of zirconia particularly after yttria incorporation [Appl. Catal. B 62 (2005) 236]. Novel developments of more stable ceria-zirconia based catalysts are reported in this study. Further stabilisation and enhancement in activity have been discussed on the basis of oxygen mobility related to structural properties. (C) 2010 Elsevier B.V. All rights reserved.

10aCeria-zirconia based catalysts10aGreenhouse gas10aN(2)O catalytic decomposition10aNitric acid plant10aNitrous oxide1 aEsteves, P.1 aWu, Y.1 aDujardin, Christophe1 aDongare, Mohan, K.1 aGranger, P. uhttps://library.ncl.res.in/content/ceria-zirconia-mixed-oxides-thermal-resistant-catalysts-decomposition-nitrous-oxide-high-001886nas a2200277 4500008004100000022001400041245014000055210006900195260007300264300001200337490000700349520085800356653002101214653001601235653002901251653001801280653003401298100001901332700002801351700002301379700002401402700002101426700002501447700001601472856012001488 2012 eng d a1566-736700aDeposition-precipitation versus anionic-exchange Au/Al2O3 catalysts: a comparative investigation towards the selective reduction of NOx0 aDepositionprecipitation versus anionicexchange AuAl2O3 catalysts aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcSEP a225-2300 v263 a

Catalytic properties of supported gold catalysts on gamma-Al2O3 prepared by a conventional deposition-precipitation method were compared with those obtained by anionic-exchange for the reduction of NOx by hydrocarbon under lean conditions that simulate Diesel engine exhaust gas. Interestingly, a catalytic activity enhancement is observed after thermal ageing under reactive conditions at 500 degrees C on anionic-exchanged samples which make them suitable for practical developments. On the other hand, the reverse trend is observed on the solids prepared by deposition-precipitation which deactivate at low temperature. Such changes in catalytic properties have been tentatively explained on the basis of textural and structural modifications taking place during thermal ageing under wet atmosphere. (C) 2012 Elsevier B.V. All rights reserved.

10aAnionic-exchange10aAu catalyst10aDeposition-precipitation10aNOx abatement10aSelective catalytic reduction1 aNguyen, D., L.1 aUmbarkar, Shubhangi, B.1 aDongare, Mohan, K.1 aLancelot, Christine1 aGirardon, J., S.1 aDujardin, Christophe1 aGranger, P. uhttps://library.ncl.res.in/content/deposition-precipitation-versus-anionic-exchange-aual2o3-catalysts-comparative-001810nas a2200277 4500008004100000022001400041245013400055210006900189260007500258300001200333490000700345520077700352653002101129653002201150653002901172653001801201653003401219100002001253700002801273700002301301700002401324700002101348700002501369700001601394856012201410 2013 eng d a1022-552800aPromising stability of gold-based catalysts prepared by direct anionic exchange for DeNO (x) applications in lean burn conditions0 aPromising stability of goldbased catalysts prepared by direct an a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGER/PLENUM PUBLISHERScMAY a157-1640 v563 a

Supported gold catalysts on gamma-Al2O3 have been investigated in the catalytic reduction of NO (x) in simulated Diesel exhaust gas conditions. Different parameters have been examined essentially the mode of gold incorporation via classical deposition-precipitation and anionic exchange methods and the nature of the pre-activation thermal treatment. The resistance to thermal ageing under reactive conditions at 500 A degrees C was found completely different with a significant rate enhancement on anionic-exchange samples. Further comparisons also show that the nature of the pre-activation thermal treatment influences the extent of surface reconstructions during thermal ageing with a detrimental effect of reductive pre-treatment on the catalytic performances.

10aAnionic-exchange10aAu/Al2O3 catalyst10aDeposition-precipitation10aNOx abatement10aSelective catalytic reduction1 aNguyen, D., -L.1 aUmbarkar, Shubhangi, B.1 aDongare, Mohan, K.1 aLancelot, Christine1 aGirardon, J., S.1 aDujardin, Christophe1 aGranger, P. uhttps://library.ncl.res.in/content/promising-stability-gold-based-catalysts-prepared-direct-anionic-exchange-deno-x-001941nas a2200301 4500008004100000022001400041245014000055210006900195260007300264300001000337490000800347520087400355653002001229653002101249653002101270653001101291100002001302700001901322700002301341700002801364700001301392700002101405700002501426700002401451700002401475700001601499856012401515 2015 eng d a0926-337300aRational preparation of Ag and Au bimetallic catalysts for the hydrocarbon-SCR of NOx: sequential deposition vs. coprecipitation method0 aRational preparation of Ag and Au bimetallic catalysts for the h aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJAN a11-200 v1623 a

This study emphasizes the importance of the preparation method for bimetallic Au-Ag catalysts supported on alumina in the selective reduction of NOx by hydrocarbons with gas feed compositions representative of diesel fuelled engine exhaust gas. An optimal balance between oxidative and reductive surface properties is obtained when Au and Ag are successively introduced. Significant re-dispersion processes take place when the catalyst runs at 500 degrees C leading to a gain in activity at low temperature and ascribed to a better interaction between Au and Ag species. Co-precipitation leads to a preferential formation of intermetallic Au-Ag particles which is detrimental to the catalytic performances. Aging at 500 degrees C leads to a significant particle sintering and a strengthening of the metallic character. (C) 2014 Elsevier B.V. All rights reserved.

10aAu-Ag particles10aCo-precipitation10aDeNO(x) reaction10aHC-SCR1 aMore, Pavan, M.1 aNguyen, D., L.1 aDongare, Mohan, K.1 aUmbarkar, Shubhangi, B.1 aNuns, N.1 aGirardon, J., S.1 aDujardin, Christophe1 aLancelot, Christine1 aMamede, Anne-Sophie1 aGranger, P. uhttps://library.ncl.res.in/content/rational-preparation-ag-and-au-bimetallic-catalysts-hydrocarbon-scr-nox-sequential-001922nas a2200181 4500008004100000245012700041210006900168260000800237300001000245490000800255520125900263100001701522700002001539700002101559700001601580700001701596856012701613 2018 eng d00aBimetallic Au-Ag/Al2O3 as efficient catalysts for the hydrocarbon selective reduction of NOx from lean burn engine exhaust0 aBimetallic AuAgAl2O3 as efficient catalysts for the hydrocarbon  cMAY a23-310 v3063 aCatalytic properties of Au-Ag/Al2O3 catalysts, prepared by successive impregnation, have been investigated for the hydrocarbon selective catalytic reduction (HC-SCR) of NOx. The performances of pre-reduced and aged catalysts were evaluated on synthetic reaction mixtures with gas compositions representative of the exhaust of Diesel powered engines. An optimal 2 wt.% Ag loading was chosen and the order of introduction during sequential impregnation of Ag or Au on respectively pre-impregnated Au/Al2O3 and Ag/Al2O3 substrates was investigated revealing drastic changes on the catalytic properties after aging. XPS analysis shows a significant silver enrichment irrespective of the preparation route and aging conditions whereas ex situ UV-vis DRS analysis reveals significant electronic disturbances which reflect different interactions between Au and Ag in fresh and aged Au-Ag/Al2O3 and Ag-Au/Al2O3 catalysts. As a consequence, significant rate enhancements in NOx conversion were observed with the superior performance of Au-Ag/Al2O3 but a lower resistance to deactivation at high temperature explained by different behaviour towards redispersion/agglomeration processes highlighted from TEM observations. (C) 2016 Elsevier B.V. All rights reserved.1 aMore, P., M.1 aDongare, M., K.1 aUmbarkar, S., B.1 aGranger, P.1 aDujardin, C. uhttps://library.ncl.res.in/content/bimetallic-au-agal2o3-efficient-catalysts-hydrocarbon-selective-reduction-nox-lean-burn01935nas a2200205 4500008004100000245010300041210006900144260000800213300001000221490000800231520124200239100002501481700001301506700001601519700001501535700001801550700002001568700001601588856012501604 2018 eng d00a Enhanced selectivity of 3-D ordered macroporous Pt/Al2O3 catalysts in nitrites removal from water0 aEnhanced selectivity of 3D ordered macroporous PtAl2O3 catalysts cAUG a26-320 v5643 aTailored macroporous mesoporous alumina supports have been successfully prepared using a single hard templating approach. Pt nanoparticles, showing similar physico-chemical properties, were homogeneously dispersed throughout the different alumina frameworks as catalytic active phase for drinking water treatment. We demonstrated that careful modification of pore properties of the catalyst (size and connectivity) by pseudomorphic transformation can strongly modulate the reaction rate and selectivity through the limited access to Pt active sites within the alumina porous particles. Specifically, 3-D Ordered Macroporous Pt-Al2O3 catalysts with a high degree of interconnectivity yield to superior catalytic properties (enhanced activity and selectivity) over pure mesoporous counterparts in the hydrogenation of nitrites in water. We found that large pores (240 nm) interconnected with windows (110 nm) alleviate mass transfer limitations and clearly improve NZ selectivity. The findings of this study further suggest the possibility of engineering the pore architecture of the support to fine tune the selectivity for a particular reaction rather than investigating more on tuning the properties of the costly active metallic phase.1 aSekhar, A., C. Sunil1 aZaki, A.1 aTroncea, S.1 aCasale, S.1 aVinod, C., P.1 aDacquin, J., P.1 aGranger, P. uhttps://library.ncl.res.in/content/enhanced-selectivity-3-d-ordered-macroporous-ptal2o3-catalysts-nitrites-removal-water01701nas a2200157 4500008004100000245016000041210006900201260000800270300001400278490000700292520105800299100001601357700001601373700001901389856013501408 2019 eng d00aWhat news in the surface chemistry of bulk and supported vanadia based SCR‐catalysts: improvements in their resistance to poisoning and thermal sintering0 aWhat news in the surface chemistry of bulk and supported vanadia cOCT a1813-18280 v193 a

This paper reports a short review on the impact of poisoning effects and thermal aging on the reactivity of surface vanadate species on benchmark V2O5−WO3/TiO2 Selective‐Catalytic‐Reduction catalysts. A renewed interest of this SCR technology is related to its diversification notably as after‐treatment systems to treat the exhaust from Diesel engines with higher running temperature especially when SCR catalysts are coated on Diesel Particulates Filters. Particular attention is also paid to poisoning effects in conjunction with the progressive replacement of fossil fuels by bio‐fuels containing alkaline contaminants which drastically deactivate the catalyst through neutralization of strong acid sites. Most of the investigations show that better insight into the mechanisms of poisoning and aging processes is needed especially to understand the relative sensibility of various vanadate species. This could provide original guidelines to catalyst preparation and or the developments of more stable bulk systems as exemplified.

1 aGranger, P.1 aSiaka, H.W.1 aUmbarkar, S.B. uhttps://library.ncl.res.in/content/what-news-surface-chemistry-bulk-and-supported-vanadia-based-scr%E2%80%90catalysts-improvements