Currently, the removal of CO from automobile exhaust is accomplished by the oxidation of CO in catalytic converters. Noble metals catalysts are used on different supports but the problem is that they are rare and expensive
(1). The goal is to have highly efficient catalysts for the reaction at low costs. The same reaction known as PROX (Preferential CO Oxidation) in a hydrogen- rich stream is important for PEMFC (Proton-exchange membrane fuel cells) which uses a Pt anode. The challenge is to attain a highly selective CO oxidation reaction to purify the inlet feed from CO as best as possible and prevent the poisoning of the Pt anode
(2). This project shows that successfully synthesized nano-porous (np) Cu by the sacrificial support method
(3), and Pt single atoms embedded in the surface of np-Cu by galvanic replacement is an excellent catalyst with high surface area and superior catalytic performance for both the dry CO oxidation reaction and the PROX reaction. In these oxidative reaction environments, the Cu will be oxidized to CuO
x. Pt/np-CuO
x with a Pt loading of 0.1 at.% has shown a better catalytic conversion over the np-CuO
x control catalyst at all conditions examined. It also showed good stability and maintained its activity during long-term steady- state experiments of 45 h. The Pt/np-CuO
x catalyst also showed high selectivity when used for the PROX reaction as the selectivity stayed at 100% at a temperature as high as 140
oC. This means that the single atom Pt /np-CuO
x catalyst used in this study has a good combination of high activity, stability and selectivity for the CO oxidation and PROX reaction under widely different tested conditions.
References
[1] Li, Shanlong et al. "Copper Doped Ceria Porous Nano-structures towards a Highly Efficient Bi-functional Catalyst for Carbon Monoxide and Nitric Oxide Elimination". Chem. Sci. 6.4 (2015): 2495-2500. Web. 13 Oct. 2016.
[2] Liu, Jilei et al. "Tackling CO Poisoning with Single-Atom Alloy Catalysts". J. Am. Chem. Soc. 138.20 (2016): 6396-6399. Web. 13 Oct. 2016.
[3] Shan, Junjun et al. "Selective non-oxidative Dehydrogenation of Ethanol to Acetaldehyde and Hydrogen on Highly Dilute NiCu alloys", Appl. Catal. B: Environ. 205 (2017): 541-550.
