15:30
Unconventional catalyst synthesis and manufacturing methods 1
Chair: Victor Sebastian
15:30
20 mins
#53
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GRAPHENE AEROGEL CATALYTIC FILTER FOR AIR DISINFECTION AND PURIFICATION
King Lun Yeung
(presenter: King Lun Yeung)
Abstract: Ceria catalyst was uniformly deposited on a graphene layer and assembled into an ultralow density aerogel shown in Figure 1. It can be seen from Fig. 1b that the CeO2 complete cladded the surface of graphene and these catalyst nanoparticles are of uniform 5 nm diameter (Fig. 1c). The 2D CeO2/graphene in the aerogel forms hierarchical pores with high through porosity (Fig. 1d). Indeed, there was no observable pressure drop even at flow velocity of 160 cm3/cm2.min. The aerogel material as shown in Fig. 1e has very good mechanical strength and can resist loads of up to 3000x its weight. It is mechanically resilient and recovers its original size and shape following repeated deformation under compression loads. The material has excellent adsorption capacity for toluene vapor that is comparable to an activated carbon (Fig. 1f), but unlike the carbon adsorbent it is active for complete conversion of toluene to carbon dioxide and water once heated to its reaction temperature as shown in Fig. 1g plot. The material can be inductively heated to achieve rapid catalyst heating with minimal increase in gas temperature making it suitable for air pollution treatment in indoor environment
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15:50
20 mins
#3
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METAL CATALYSED PROCESSES AT THE SURFACE OF GRAPHENE
Andres Mollar-Cuni, David Ventura-Espinosa, Jose A. Mata
(presenter: Jose Mata)
Abstract: Graphene is a particularly interesting material to study superficial phenomena. In the lasts years, we sought to investigate the role of graphene as support for catalytic transformations. For this purpose, we developed synthetic procedures that allow direct immobilization of well-defined organometallic species and metal nanoparticles onto the surface of graphene.1–3
In this communication, we discuss the influence of graphene in catalytic transformations. The catalytic properties with and without the support are evaluated in different benchmark catalytic reactions. The results suggest that the use of graphene as support increases the stability of active species improving the catalytic activity.4-5
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16:10
20 mins
#10
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SYNTHESIS OF GRAPHENE-RELATED NANOMATERIALS BY CCVD USING A Co/CELLULOSE-DERIVED CARBON CATALYST: INFLUENCE OF THE ADDITION OF Cu OR Mn.
Wilson Henao, Pilar Tarifa, Fernando Cazaña, Nieves Latorre, Eva Romeo, Antonio Monzón
(presenter: Fernando Cazaña)
Abstract: Large-scale production of emerging carbonaceous nanomaterial (CNMs) require the design and optimization of new types of multifunctional catalysts. This work presents the selective synthesis of graphene nanosheets and carbon nanotubes (CNTs) via catalytic chemical vapor deposition (CCVD) of methane over a Co/carbon catalyst derived from cellulose (CDC). The catalysts were prepared by thermal decomposition, under reductive atmosphere, of cellulose previously impregnated with the metallic precursors. The incorporation of Mn or Cu as metallic promotors was found to direct the reaction towards the formation of a desired CNM. Co-Mn/CDC catalyst was more selective to the production of graphene nanosheets at temperatures above 900 °C (Figure 1c), whereas Co-Cu/CDC catalyst favored the formation of CNTs at temperatures below 850 °C (Figure 1d). The influence of the operating conditions (reaction temperature and CH4:H2 ratio) on the quality and productivity of the obtained CNMs was also evaluated. The productivity and growth rate of CNMs were favored by increasing these parameters. Co-Mn/CDC catalyst reached a maximum productivity of 0.49 gC/gcat∙h at 900 °C whereas in the Co-Cu/CDC this productivity was 0.3 gC/gcat∙h at 800 °C. The growth mechanism and the carbon mass evolution were further analyzed by a phenomenological kinetic model developed in previous works.
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