Revista de nanomateriales y nanotecnología molecular

Towards Methanol Electrooxidation: Comparative Study on Imidazolium and Guanidinium Ionic Liquids Supported Pt Nanocrystals on Carbon Nanotubes

Shulian He, Liping Ding, Dechao Chen, Yunjin Yao,Wenhong Liu, Lei Wan, Jinzhang Xu and Shiding Miao

Towards Methanol Electrooxidation: Comparative Study on Imidazolium and Guanidinium Ionic Liquids Supported Pt Nanocrystals on Carbon Nanotubes

In this work, two types of ionic liquids (ILs), 1-hexadecyl-3-methylimidazolium chloride (C₁₆MIMCl) and 1,1,3,3-tetramethyl guanidinium bromide (TMGBr), were employed to assist the immobilization of Pt nanocrystals on carbon nanotubes (CNTs). It is found that the conjugated effects including the cations-π (C-N⁺•), π-π interactions and electrostatic interactions are the main drive forces between the quasi-aromatic imidazolium ring and pyrolytic graphite of CNTs in sample of C₁₆MIM-CNTs-Pt. The interactions of intra-molecular hydrogen bonds (N⁺-H•••N) and electrostatic interactions are found in the guanidinium ILs assisted catalysts (TMG-CNTs-Pt). The conjugated effects induce the formation of Pt(II) complexes in the composites even after the platinum precursor (H₂PtCl₆•6H₂O) was reduced by NaBH₄. The catalysis investigation towards methanol oxidation carried out in acidic solution demonstrates that both ternary composite (C₁₆MIM-CNTs- Pt and TMG-CNTs-Pt) catalysts exhibit higher electro-catalytic activity and better stability than the binary catalyst (CNTs-Pt) or the single-component catalyst (Pt nanocrystals).