Cu Mixed Oxides Based on Hydrotalcite-Like Compounds for the Oxidation of Trichloroethylene

Abstract

Different Cu/(Mg or Ni)/Al mixed oxides based on hydrotalcite-like compounds have been studied for the catalytic oxidation of trichloroethylene. The catalysts have been synthesized and characterized by different techniques such as N2-adsorption, inductively coupled plasma (ICP), X-ray diffraction, and temperature-programmed reduction (TPR). It has been shown that the activity for the catalytic abatement of trichloroethylene depends on the presence of metals with redox properties in the catalyst composition. The best results have been obtained with containing copper mixed oxides, although there is no direct correspondence between the copper content and the catalyst activity. These catalysts are highly active and selective, CO2 and HCl being the main reaction products. A mechanism for the reaction has been proposed.

Ni−Cu Hydrotalcite‐Derived Mixed Oxides as Highly Selective and Stable Catalysts for the Synthesis of β‐Branched Bioalcohols by the Guerbet Reaction

“…The BET surfacea rea slightly depended on the Cu 2 + /Ni 2 + ratio used in the materials, as pre-viously reportedb yB lanch-Raga et al [10] and Tanasoi et al [11] for different CuÀ(Mg or Ni)ÀAl mixed oxides. The BET surfacea rea slightly depended on the Cu 2 + /Ni 2 + ratio used in the materials, as pre-viously reportedb yB lanch-Raga et al [10] and Tanasoi et al [11] for different CuÀ(Mg or Ni)ÀAl mixed oxides.…”

“…The synthesized materials were named as follows depending on the NiÀCu ratio used during the synthesis:C u(10), Ni(2.5)Cu(7.5), Ni(5.0)Cu(5.0), Ni(7.5)Cu(2.5) and Ni (10). Cu(10, for example, corresponds to Cu 0.8 Mg 5.2 Al 2 O 9 mixed oxide and Ni(7.5)Cu(2.5) to Ni 0.6 Cu 0.2 Mg 5.2 Al 2 O 9 .T he chemical composition, given by X-ray fluorescence (XRF) spectroscopy and the BET surfacea rea of the mixed oxideso btained after calcination of the synthesizedh ydrotalcites(HTs) are given in Ta ble 1.…”

“…The XRD patterns of the as-synthesized HTsp resent the diffraction lines typical for ah ydrotalcite compound,i ndependently of the Ni/Cu ratio used ( Figure 1a;J CPDS . [12] The d- NiþCu ðNiþCuþMgþAlÞ [b] Cu (10) (10);B)Ni(2.5)Cu(7.5);C )Ni(5.0)Cu(5.0); D) Ni(7.5)Cu(2.5);E)Ni (10). ChemSusChem 2016, 9,3196 -3205 www.chemsuschem.org spacingv alues calculated for the (003) diffraction peaks for all materials were close to 7.8 ,w hich is consistent with an interlayer gallery height of 3.0 ,w here carbonate species behave as charge-balancing anions.…”

The oxidation of trichloroethylene over different mixed oxides derived from hydrotalcites

“…As it can be seen, the catalyst was stable at this temperature and there was not a significant deactivation after 70 hours of reaction. These results indicate that Co-containing mixed oxides based on hydrotalcite-like compounds are highly active and stable catalysts for the TCE oxidation, being these results better than those obtained with an acid zeolite or with other type of catalysts based on bronzes or on Cu hydrotalcites [15,17].…”

“…By changing the nature and the molar ratio of the metal cations as well as the type of interlayer anions, many isostructural materials with different physicochemical properties can be obtained. The calcination of hydrotalcites leads to the formation of mixed oxides with interesting properties for the CVOC´s catalytic removal, such as small particle size, large specific area and homogeneous interdispersion of the metals [17][18][19][20]. This work studies the use of mixed oxides derived from hydrotalcites, containing transition metals with oxidative properties, for the TCE catalytic oxidation reaction.…”