Encapsulating Nitrogen-Doped Tin Dioxide Nanoparticles in Multi-Walled Carbon Nanotubes via Melt-Infiltration as Support of Pt Catalyst for Dimethyl Ether

The slow kinetics and pronounced CO poisoning of the dimethyl ether oxidation reaction (DOR) limit the development of direct dimethyl ether fuel cells. In this work, a hybrid support was constructed in which nitrogen-doped tin oxide (N-SnO2) nanoparticles were encapsulated inside multiwalled carbon nanotubes (MWCNTs) through a melt-infiltration and in situ doping approach. Pt nanoparticles were then deposited by ethylene glycol reduction, yielding a core–shell structured Pt/N-SnO2@MWCNT catalyst. Nitrogen doping (N-doping) introduces abundant oxygen vacancies, which effectively anchor and stabilize highly dispersed Pt nanoparticles, leading to a unique triple-phase Pt–N–SnO2–MWCNTs interface. The resulting catalyst exhibits an electrochemical active surface area (ESA) of 113.45 m2·g–1 and delivers a superior DOR mass activity of 250.74 mA·mgpt–1. It also shows improved durability, retaining 74.2% of its initial ESA after 5000 cycles, together with a lower charge transfer resistance of 7.82 Ω·cm–2. The enhanced performance originates from the synergy between oxygen vacancy-stabilized Pt dispersion, the distinctive triple-phase interface, and a strong metal–support interaction. This study offers a viable route for designing high-performance electrocatalysts toward efficient DOR.