Synthesis and characterization of Cu–Zn/TiO₂for the photocatalytic conversion of CO₂to methane

Abstract

Different Cu-Zn/TiO catalysts were synthesized by using the wet impregnation method. The prepared catalysts were used for the conversion of CO into methane by photocatalysis. Various characterization techniques were used to observe the surface morphology, crystalline phase, Brunauer-Emmett-Teller (BET) surface area, presence of impregnated Cu and Zn, and functional group. Scanning electron microscope analysis showed spherical morphology, and slight agglomeration of catalyst particles was observed. BET analysis revealed that the surface area of the catalyst was decreased from 10 to 8.5 m/g after impregnation of Cu and Zn over TiO support. Synergetic effect of Cu and Zn over TiO support (Cu/TiO, Zn/TiO and Cu-Zn/TiO) and the effects of Cu loading (0, 1.8, 2.1, 2.6 and 2.9 wt%) were also investigated at different feed molar ratios of H/CO (2:1 and 4:1). The Cu-Zn/TiO catalyst showed a maximum conversion of 14.3% at a feed molar ratio of 4. The addition of Zn over the catalyst surface increased the conversion of CO from 10% to 14.3% which might be due to synergy of Cu and Zn over TiO support.

Efficient Advanced Oxidation Process (AOP) for Photocatalytic Contaminant Degradation Using Exfoliated Metal-Free Graphitic Carbon Nitride and Visible Light-Emitting Diodes

“…Figure 9 shows the influence of pH on phenol degradation. The photodegradation efficiency of phenol at acidic pH (2)(3)(4)(5) was better than at basic pH (9)(10)(11)(12). Almost 97% of phenol degradation was achieved in 60 min of reaction time at acidic pH compared with 100% for natural pH in 90 min and 80% at basic pH in 180 min, a similar pH dependency was shown in the literature [47,54].…”

Study of the structural and morphological properties of copper catalysts supported on Al2O3 and TiO2 synthesized by the impregnation method

“…The broadband range of 1500 to 700 cm -1 comprises two types of bonds, Al-O-H and Al-O bonds. The 1300 cm -1 region is related to the OH group present on the surface, and the region below 1000 cm -1 is characterized by metal-oxygen bonds [23]. For the Cu/TiO 2 catalyst, were observed the absorption bands at 3439, 3369, 3300, 1652, 737 and 676 cm -1 .…”

“…For the Cu/TiO 2 catalyst, were observed the absorption bands at 3439, 3369, 3300, 1652, 737 and 676 cm -1 . The peaks at 3439 -3300 cm -1 and 1652 cm -1 were attributed to O-H bending, and the bands observed from 400 -900 cm -1 corresponded to Ti-O Anatase stretching vibrations [23].…”

“…The bands at 3385 cm −1 and 1635 cm -1 were attributed to O-H bending, which can be due to physically adsorbed water [21]. The vibrations of hydroxyl groups comprise the O-H stretch derived from two contributions: (1) non-dissociated O-H species and (2) O-H species (dissociated from H 2 O), both adsorbed [22,23]. The broadband range of 1500 to 700 cm -1 comprises two types of bonds, Al-O-H and Al-O bonds.…”

“…Wang et al [28] worked with TiO 2 and showed that the calcination process affect the morphology of the samples, after calcination treatment the samples are composed of larger agglomerated particles. Rana et al [23] synthesized Cu 2.6 -Zn 0.5 /TiO 2 catalyst at different magnifications. The rough spherical morphology and slight agglomeration can be seen on the structure of catalyst, the slight agglomeration present on the surface might be due to the sintering during the calcination process.…”