Uma estratégia simples para suportar nanopartículas de paládio em nanotubos de carbono usando Polivinilpirrolidona como modificador de superfície

• Processo: 14/20717-0
• Modalidade de apoio: Auxílio à Pesquisa - Publicações científicas - Artigo
• Data de Início da vigência: 01 de novembro de 2014
• Data de Término da vigência: 30 de abril de 2015
• Área do conhecimento: Ciências Exatas e da Terra - Química - Química Inorgânica
• Pesquisador responsável: Pedro Henrique Cury Camargo
• Beneficiário: Pedro Henrique Cury Camargo
• Instituição Sede: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brasil
• Assunto(s): Materiais nanoestruturados Polímeros Nanopartículas Eletrocatálise
• Palavra(s)-Chave do Pesquisador: electrocatalysis | nanoparticles | nanotubes | palladium | polymers | nanomateriais

Resumo

This paper describes the development of a facile and environmentally friendly strategy for supporting with palladium nanoparticles (Pd NPs) on multi-walled carbon nanotubes (MWCNTs) employing ethanol as the solvent/reducing agent, potassium tetrachloropalladate (II) (K2PdCl4) as the Pd precursor, and polyvinylpyrrolidone (PVP) as the surface-modifier. More specifically, our approach was based on the non-bonding interaction between MWCNTs and polyvinylpyrrolidone (PVP), which is a cheap, non-toxic, and commercial polymer. As PVP can serve not only as a surface-modifier but also as a stabilizing agent for Pd NPs, the utilization of additional functionalization steps, reducing agents, and stabilizers was not required to achieve the uniform Pd deposition over MWCNTs. Our results demonstrated that Pd NPs below 5 nm in diameter could be directly supported on MWCNTs by this route. Also, sequential Pd reduction steps could be employed to improve the coverage of Pd NPs at the MWCNTs surface, but also led to the formation of larger Pd particles/aggregates. The electrocatalytic activitiy for ethanol oxidation was investigated as a function of the composition and structure of the produced materials, in which MWCNTs decorated with Pd NPs of smaller sizes and lower coverage displayed the highest activities. The results described herein suggest that our approach may serve as a simple platform for the synthesis of MWCNTs decorated with metal NPs with well-defined morphologies and uniform dispersion for electrochemical and catalytic applications. (AU)