Pt2CeO2 Heterojunction Supported on Multiwalled Carbon Nanotubes for Robust Electrocatalytic Oxidation of Methanol

Pingping Yang; Xuejiao Wei; Li Zhang; Shiming Dong; Wenting Cao; Dong Ma; Yuejun Ouyang

doi:10.3390/molecules28072995

Pt₂CeO₂ Heterojunction Supported on Multiwalled Carbon Nanotubes for Robust Electrocatalytic Oxidation of Methanol

Molecules. 2023 Mar 27;28(7):2995. doi: 10.3390/molecules28072995.

Authors

Pingping Yang^{1

2}, Xuejiao Wei¹, Li Zhang¹, Shiming Dong¹, Wenting Cao¹, Dong Ma¹, Yuejun Ouyang^{1

2}

Affiliations

¹ College of Chemistry and Materials Engineering, Huaihua University, Huaihua 418008, China.
² Hunan Engineering Research Center for Recycled Aluminum, Huaihua University, Huaihua 418008, China.

Abstract

Herein, we prepared Pt₂CeO₂ heterojunction nanocluster (HJNS) on multiwalled carbon nanotubes (MWCNTs) in deep eutectic solvents (DESs) which is a special class of ionic liquids. The catalyst was then heat-treated at 400 °C in N₂ (refer to Pt₂CeO₂/CNTs-400). The Pt₂CeO₂/CNTs-400 catalyst showed remarkably improved electrocatalytic performance towards methanol oxidation reaction (MOR) (839.1 mA mg_Pt^-1) compared to Pt₂CeO₂/CNTs-500 (620.3 mA mg_Pt^-1), Pt₂CeO₂/CNTs-300 (459.2 mA mg_Pt^-1), Pt₂CeO₂/CNTs (641.6 mAmg^-1) (the catalyst which has not been heat-treated) and commercial Pt/C (229.9 mAmg^-1). Additionally, the Pt₂CeO₂/CNTs-400 catalyst also showed better CO poisoning resistance (onset potential: 0.47 V) compared to Pt₂CeO₂/CNTs (0.56 V) and commercial Pt/C (0.58 V). The improved performance of Pt₂CeO₂/CNTs-400 catalyst is attributed to the addition of appropriate CeO₂, which changed the electronic state around the Pt atoms, lowered the d-band of Pt atoms, formed more Ce-O-Pt bonds acting as new active sites, affected the adsorption of toxic intermediates and weakened the dissolution of Pt; on the other hand, with the assistance of thermal treatment at 400 °C, the obtained Pt₂CeO₂ HJNS expose more new active sites at the interface between Pt and CeO₂ to enhance the electrochemical active surface area (ECSA) and the dehydrogenation process of MOR. Thirdly, DES is beneficial to the increase of the effective component Pt(0) in the carbonization process. The study shows a new way to construct high-performance Pt-CeO₂ catalyst for the direct methanol fuel cell (DMFC).

Keywords: Ce-O-Pt bonds; Pt2CeO2 heterojunction nanocluster; deep eutectic solvents; direct methanol fuel cell; methanol oxidation reaction.

Grants and funding

This research was funded by the Key Project of Hunan Provincial Education Department of China (22A0551), the Natural Science Foundation of Hunan Province (2020JJ4073), Hunan Provincial general project of Education Department (21C0645). Key project of Huaihua University (HHUY2021-03).