Issue 8, 2023

Oxidation of ethylene by Cu/TiO2: reducibility of Cu2+ in TiO2 as a possible descriptor of catalytic efficiency

Abstract

Catalytic oxidation using non-noble metal-based catalysts is a promising approach to mitigate pollution due to VOCs in the air. In this work, mesoporous Cu/TiO2 catalysts containing different concentrations of Cu2+ (0.2, 1, 3, and 4 wt% Cu w.r.t. Ti) were synthesized using the sol–gel technique. The catalysts were characterized using inductively coupled plasma-optical emission spectrometry, XRD, Raman spectroscopy, N2 physisorption, cyclic voltammetry, H2-TPR and electron microscopy to understand the structure and composition. The thermal catalytic gas phase oxidation of ethylene was studied by heating a mixture of ethylene (1.5 vol%) and air (5.9 vol%) in the presence of the Cu/TiO2 samples in the temperature range of 298 to 773 K. Cu/TiO2 showed a higher catalytic activity compared to TiO2 for the thermal oxidation of ethylene, indicating a strong promotion by doped copper ions. A volcanic behaviour in the catalytic activity was observed with different concentrations of Cu doping, with 1% Cu/TiO2 showing a 99.5% ethylene conversion at 673 K and 100% selectivity to CO2. The activity of 1% Cu/TiO2 remained consistent without deactivation for 24 h. At low dopant concentrations of Cu (0.2 and 1% Cu/TiO2), the reduction of Cu2+ to Cu+ was observed. An interplay of oxygen vacancies (OV), Cu+, Cu2+ and Ti4+ may be involved in controlling the activity. DRIFT studies indicated the formation of surface bidendate carbonate as a possible intermediate.

Graphical abstract: Oxidation of ethylene by Cu/TiO2: reducibility of Cu2+ in TiO2 as a possible descriptor of catalytic efficiency

Supplementary files

Article information

Article type
Paper
Submitted
27 12 2022
Accepted
09 3 2023
First published
30 3 2023
This article is Open Access
Creative Commons BY-NC license

Catal. Sci. Technol., 2023,13, 2330-2339

Oxidation of ethylene by Cu/TiO2: reducibility of Cu2+ in TiO2 as a possible descriptor of catalytic efficiency

K. Rajendran, M. Sharma, A. Jaison, M. Ankitha, A. D. Tiwari, C. P. Vinod and D. Jagadeesan, Catal. Sci. Technol., 2023, 13, 2330 DOI: 10.1039/D2CY02170F

This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. You can use material from this article in other publications, without requesting further permission from the RSC, provided that the correct acknowledgement is given and it is not used for commercial purposes.

To request permission to reproduce material from this article in a commercial publication, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party commercial publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements