Physico-Chemical and Catalytic Properties of Mesoporous CuO-ZrO2 Catalysts

Abstract

Mesoporous CuO-ZrO 2 catalysts were prepared and calcined at 500˝C. The performance of the synthesized catalysts for benzylation of benzene using benzyl chloride was studied. The bare support (macroporous ZrO 2 ) offered 45% benzyl chloride conversion after reaction time of 10 h at 75˝C. Significant increase in benzyl chloride conversion (98%) was observed after CuO loading (10 wt. %) on porous ZrO 2 support. The conversion was decreased to 80% with increase of CuO loading to 20 wt. %. Different characterization techniques (XRD, Raman, diffuse reflectance UV-vis, N 2 -physisorption, H 2 -TPR, XPS and acidity measurements) were used to evaluate physico-chemical properties of CuO-ZrO 2 catalysts; the results showed that the surface and structural characteristics of the ZrO 2 phase as well as the interaction between CuO-ZrO 2 species depend strongly on the CuO content. The results also indicated that ZrO 2 support was comprised of monoclinic and tetragonal phases with macropores. An increase of the volume of monoclinic ZrO 2 phase was observed after impregnation of 10 wt. % of CuO; however, stabilization of tetragonal ZrO 2 phase was noticed after loading of 20 wt. % CuO. The presence of low-angle XRD peaks indicates that mesoscopic order is preserved in the calcined CuO-ZrO 2 catalysts. XRD reflections due to CuO phase were not observed in case of 10 wt. % CuO supported ZrO 2 sample; in contrast, the presence of crystalline CuO phase was observed in 20 wt. % CuO supported ZrO 2 sample. The mesoporous 10 wt. % CuO supported ZrO 2 catalyst showed stable catalytic activity for several reaction cycles. The observed high catalytic activity of this catalyst could be attributed to the presence of a higher number of dispersed interactive CuO (Cu 2+ -O-Zr 4+ ) species, easy reducibility, and greater degree of accessible surface Lewis acid sites.

Low Temperature Oxidation of Carbon Monoxide over Mesoporous Au-Fe2O3Catalysts

“…A standard dual anode excitation source with Mg K (1253.6 eV) radiation was used at 13 kV and 100 W. H 2 -temperature programmed reduction profiles for all the catalyst samples were collected using Quantachrome CHEMBET-3000 instrument. More details of the experimental procedures used in this work can be found in our previous publications [7,22].…”

“…The sample preparation procedure for elemental analysis and a detailed description of the experimental procedure were described in our previous publication [22]. The powder X-ray diffraction measurements for the samples were performed using Bruker D8 Advance target diffractometer.…”

“…A detailed procedure was described in our previous publication [22] to determine the specific surface area, pore volume, and average pore radius of the samples. The X-ray photoelectron spectroscopy measurements for all the samples were carried out using a SPECS GmbH XPS instrument.…”

“…The XRD patterns were obtained using Cu K radiation ( = 1.5405Å) at 40 kV and 40 mA. The identification of phases presented in the samples and crystallite sizes of iron oxide and gold metal were calculated using Scherrer equation as described in our previous publication [22].…”

SnO2 -TiO2 structures and the effect of CuO, CoO metal oxide on photocatalytic hydrogen production

“…The results show that the specific surface area calculated by the BET method of ST with co‐catalysts is lower than that obtained for ST material. This result suggests that the co‐catalysts (CoO and CuO) are well dispersed on the surface of ST material, decreasing pore volume and pore size …”