CeO2 nanorods supported CuOx-RuOx bimetallic catalysts for low temperature CO oxidation

Md Robayet Ahasan; Ruigang Wang

doi:10.1016/j.jcis.2023.10.113

CeO₂ nanorods supported CuO_x-RuO_x bimetallic catalysts for low temperature CO oxidation

J Colloid Interface Sci. 2024 Jan 15;654(Pt B):1378-1392. doi: 10.1016/j.jcis.2023.10.113. Epub 2023 Oct 24.

Authors

Md Robayet Ahasan¹, Ruigang Wang²

Affiliations

¹ Department of Metallurgical and Materials Engineering, The University of Alabama, Tuscaloosa, AL 35487, United States.
² Department of Metallurgical and Materials Engineering, The University of Alabama, Tuscaloosa, AL 35487, United States. Electronic address: rwang@eng.ua.edu.

PMID: 37918097
DOI: 10.1016/j.jcis.2023.10.113

Abstract

Bimetallic catalysts often outperform monometallic catalysts due to changeable structural orientation, synergistic effects, and integration of two different metal or metal oxide properties. Here, a series of CeO₂ nanorods (NR) supported bimetallic CuO_x and RuO_x catalysts (Cu: Ru ratios of 9:1, 7:3, and 5:5) were prepared using a wet impregnation method. In situ DRIFTS, H₂ temperature programmed reduction (H₂-TPR), CO temperature programmed desorption (CO-TPD), and other characterization techniques were used to investigate the effect of the Cu:Ru ratio on the activity of low-temperature CO oxidation. Among three catalysts, CeO₂ NR supported 7 wt% Cu-3 wt% Ru catalyst after a reduction activation treatment showed the best performance with 100 % CO conversion at 166 °C and the lowest activation energy of 18.37 kJ mol^-1. Raman and XPS profiles revealed that the origin of the superior performance is at least partially related to the high surface oxygen vacancy concentration and other distinct oxygen species (physi-/chemi-sorbed oxygen and bulk lattice oxygen), leading to outstanding adsorption and oxidation property of CO.

Keywords: CO oxidation; CO-TPD; CeO(2) nanorods; CuO(x)-RuO(x) bimetallic catalyst; In situ DRIFTS.