Oxidation of Carbon Monoxide Over SBA-15-Confined Copper, Palladium and Iridium Nanocatalysts

García-Cuello, Vanessa S.; Giraldo, Liliana; Moreno–Piraján, Juan Carlos

doi:10.1007/s10562-011-0691-2

Cited by 10 publications

(10 citation statements)

References 33 publications

(40 reference statements)

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“…Many earlier studies focusing on modification of SBA-15 are based on physical mixing 35 , however, improved procedures can improve the interface between different components of hybrid materials that promote their activity in the target application [36][37][38] . The most common methods are in-situ incorporation [39][40][41][42][43] , co-precipitation / deposition-precipitation [44][45][46][47][48] , post-grafting 49,50 , impregnation [51][52][53][54][55] , incipient wetness impregnation 31,42,[56][57][58] , and infiltration 59,60 . A crucial issue for almost all of these methods is to obtain uniform distribution of the modifier throughout the catalyst 61 .…”

Section: Sba-15 Modification Routesmentioning

confidence: 99%

“…Post-grafting 49 Infiltration 59,73 is a technique that focuses on the minimization of the outer-mesoporous particle attachment of the metal nanoparticles. For that purpose, the outer surface of the mesoporous particles is first passivated, and then the inner surface of the mesopores is activated with functional groups.…”

Section: Sba-15 Modification Routesmentioning

confidence: 99%

“…There are many catalytically active elements that have been studied for heterogeneous catalysis of CO2 hydrogenation process, and the selection of one or two of these elements depend mostly on the desired product. Ru 100 , Rh 139 , Pd 59,88,140 , Ir 59 and Pt 140 based catalysts have been investigated widely due to their high efficiency in dissociating H2 and the fact that they are more coke resistant 59,68,80 . However, Cu, Ni and Co-based catalysts maintained their popularity due to their low cost-to-yield ratio 68 .…”

Section: Catalysts For Co2 Hydrogenationmentioning

confidence: 99%

“…However, Cu, Ni and Co-based catalysts maintained their popularity due to their low cost-to-yield ratio 68 . As for the products of the CO2 hydrogenation process, Cu based catalysts 46,53,59,84,86 can yield CO, various hydrocarbons such as gasoline, alcohols and fuels like methanol and dimethyl ether via methanol route 68 whereas Ni or Co-based catalysts mostly yield methane 68,141 . Dimethyl ether production mainly depends on the acidity of the final catalyst.…”

Section: Catalysts For Co2 Hydrogenationmentioning

confidence: 99%

“…Silica has been reported as a high stability support for Cu active phase to be used in various hydrogenation and dehydration reactions 46,68,99,157 and it was shown to increase the methanol yield through CO2 hydrogenation by providing additional positive surface charge due to the Cu-SiO2 bonds at the interface 106,158,159 . Mesoporous silica can be prepared with a very high specific surface area (can be more than 700 m 2 /g) and uniform pore size distribution enabling improved dispersion and controllable particle size of the active phase nanoparticles 53,59,147 . High surface area of the support is beneficial not only to obtain a large catalytically active metal surface but also for keeping the active sites isolated from each other which can otherwise interact with each other instead of gas phase reactant molecules 99 .…”

Section: Catalysts For Co2 Hydrogenationmentioning

confidence: 99%

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Mesoporous material systems for catalysis and drug delivery

Atakan¹

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Hybrid material systems possess multi-functional properties which make them intriguing for the materials science community since very early dates. However, it is not straightforward to produce such material systems. A smart and efficient approach is necessary to extract the desired properties of each component under the desired conditions. This study evolved to its last form primarily around this notion, where the development of a hybrid material is the core of the work. This hybrid material is then further explored for two different applications in the catalysis and drug delivery fields.A nanoassembly was established around a mesoporous silica support. SBA-15 was picked as this support among the other mesoporous silica due to its well-defined pore structure and accessible pore volume. The silica framework was doped with Zr atoms and the pores were partly infiltrated with Cu nanoparticles resulting in a hybrid material with tunable properties. SBA-15 was synthesized by a sol-gel method where a micellar solution was employed as a template for the silica framework. To achieve the doped version, a Zr precursor was added to the synthesis solution. The effects of different synthesis conditions, such as the synthesis catalyst (For a Clsalt) and the Si source (tetraethyl orthosilicate (TEOS) or sodium metasilicate (SMS)) on the characteristics of the final material were investigated. It was observed that these changes in the synthesis conditions yielded different particle morphology, pore size (11-15 nm), and specific surface area (400-700 m 2 /g). Cu nanoparticles (NPs) were grown in the (Zr-)SBA-15 support using infiltration (Inf) or evaporation induced wetness impregnation (EIWI) methods. The infiltration method is based on functionalizing the (Zr-)SBA-15 support surfaces before the Cu ion attachment whereas EIWI is based on slow evaporation of the liquid from the (Zr-)SBA-15 -Cu aqueous suspension. Both methods are designed to yield preferential growth of Cu NPs in the pores with a diameter smaller than 10 nm and in oxidized form.However, depending on the loading method used, different chemical states of the final material were achieved, i.e. Zr content and porous network properties are different.Cu-Zr-SBA-15 nanoassemblies produced under various synthesis conditions were used for the catalytic conversion of CO2 into valuable fuels such as methanol and dimethyl ether (DME). The effect of different chemical states of the catalyst arising from variations in the synthesis parameters was investigated. It was found that the Si precursor (TEOS or SMS) had a considerable impact on the overall performance of the catalyst whereas the Cu iv loading method (Inf or EIWI) changed the catalytic selectivity between DME and methanol. The activity of the catalyst was further investigated in a time-evolution study where the accumulation of each product in the gas phase and the molecular groups attached to the catalyst surface were recorded over time. Accordingly, thermodynamic equilibrium was achieved on the 14th day of the reaction ...

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