Universiti Teknologi Malaysia Institutional Repository

Properties and bifunctional catalytic activity of niobium-doped silica-titania: effect of phosphoric acid treatment

Lee, Siew Ling and Mohd. Ekhsan, Jamilah and Ling, Chui Min (2022) Properties and bifunctional catalytic activity of niobium-doped silica-titania: effect of phosphoric acid treatment. Science and Technology Indonesia, 7 (4). pp. 455-460. ISSN 2580-4405

[img]
Preview
PDF
800kB

Official URL: http://dx.doi.org/10.26554/sti.2022.7.4.455-460

Abstract

The effect of phosphoric acid treatment on the physical-chemical properties and catalytic activity of the niobium-doped silica-titania bifunctional catalyst was investigated. As part of the synthesis procedure to produce xPO4−/Nb/TiO2-SiO2, different concentrations of phosphoric acid (H3PO4) were used (x= 0, 0.05, 0.10, 0.15, 0.20, 0.25 M). As shown by XRD analysis, the samples synthesized using 0–0.20 M H3PO4 were in amorphous form, as featureless diffractograms were obtained, indicating the PO4− groups were dispersed homogeneously on the surface of Nb doped SiO2-TiO2 . Due to the increased concentration of acid, other compounds were formed in the samples by reactions between PO4− and Nb and/or Ti. Additionally, UV-Vis DRS results indicated that the presence of the PO4− group accelerated the transformation of hydrated tetrahedral Ti species into isolated tetrahedral Ti species. An experimental investigation of the catalytic performance of the catalyst was conducted using 1,2-epoxyoctane as an oxidant for the epoxidation of 1-octene to 1,2-octanediol. It has been demonstrated that H3PO4 treatment was essential for oxidative and acidity active site formation. The current research findings strongly suggested that Nb-doped TiO2-SiO2 treated with 0.2 M H3PO4 was the most effective bifunctional catalyst in generating 1,2-octanediol.

Item Type:Article
Uncontrolled Keywords:niobium, oxidative, phosphoric acid, silica
Subjects:Q Science > QD Chemistry
Divisions:Science
ID Code:98798
Deposited By: Narimah Nawil
Deposited On:02 Feb 2023 08:58
Last Modified:02 Feb 2023 08:58

Repository Staff Only: item control page