Novel amorphous mesoporous 0.25Cr2O3-0.75ZrO2 nanomaterials synthesized by a surfactant-assisted hydrothermal method for ethanol oxidation

Novel mesoporous 0.25Cr(2)O(3)-0.75ZrO(2) nanomaterials were successfully synthesized via hydrothermal method in the presence of anionic, cationic and non-ionic surfactants, namely, SDS, CTAB and Triton X-100, respectively. The effect of different surfactants and their concentrations on the physicochemical properties and the catalytic activity of the catalysts were studied by the XRD, HR-TEM, FT-IR, BET, UV-vis/DR, NH3-TPD and ethanol oxidation techniques. XRD results indicated that all the as-prepared nanomaterials were amorphous materials. The morphology study demonstrated that the sample with CTAB has the smallest particle size while that with SDS has the largest value. The catalysts prepared with non-ionic and cationic surfactants have the highest surface area and the pore volume while those prepared with anionic or without surfactant have the smallest values. Additionally, the surface area of the catalysts decreases with increasing the surfactant content. The optical study indicated that the absorption peak of the nanomaterials shifts towards the short wavelength by changing the various surfactants. It is well-observed by NH3-TPD that the non-ionic and cationic surfactants enhanced the amount of acidic sites on the catalyst surface. These results indicate that the catalytic activity of mesoporous catalysts can be improved effectively by the addition of non-ionic and cationic surfactants. (C) 2016 Elsevier B.V. All rights reserved.