(759e) Fluffy TiO2-Coating and Tin Oxide Supported Platinum for Ethanol Electro-Oxidation and Oxygen Reduction

A fluffy titanium dioxide layer on carbon nanotubes TiO₂/CNT with tin oxide (SnO₂) as a bi-functional element was used as a support for platinum nanoparticles (Pt NPs). The TiO₂-layer covered the CNTs in a fluffy morphology that showed a remarkable surface area over 300 m²/g (based on BET). The high porosity offered a high surface area for Pt NPs to be uniformly dispersed with a minimal agglomeration. The prepared catalyst exhibited a considerable electro-catalytic activity for ethanol oxidation (EOR) with a 350 mV negative shift in onset potential relative to Pt/C (E-TEK). In addition, it showed an enhancement in the durability based on i-t curve at 705 mV by ~2.2 times. The same catalyst was tested in ORR and it showed a remarkable improvement regarding the stability and the onset potential. Furthermore, the half-wave potential was recorded with a positive shift by ΔE_1/2=38 mV. Transmission electron microscopy revealed a high porous surface of TiO₂ and crystalline state of SnO₂, TiO₂, and Pt NPs. X-ray photoelectron spectroscopy revealed a positive shift in SnOx binding energy. This shift was assigned as a reason of having early onset in EOR and high catalyst stability. On the other hand, the outcomes of the ORR can be attributed to (1) TiO₂-fluffy surface stabilized SnO₂ and tin oxide helped removing OH on Pt sites (2) Modifying Pt electronic structure made it favorable toward O-O dissociation.