J. Phys. IV France 12 (2002) Pr4-29
DOI: 10.1051/jp4:20020074

Controlled-growth of platinum nanoparticles on carbon nanotubes or nanospheres by MOCVD in fluidized bed reactor

P. Serp¹, R. Feurer^{2, 3}, J.L. Faria⁴ and J.L. Figueiredo<sup>4

1</sup>  Laboratoire de Catalyse, Chimie Fine et Polymères, École Nationale Supérieure d'Ingénieurs en Arts Chimiques et Technologiques, 118 route de Narbonne, 31077 Toulouse cedex, France
²  Centre Interuniversitaire de Recherche et d'Ingénierie des Matériaux, UMR CNRSIINPT/UPS, École Nationale Supérieure d'ingénieurs en Arts Chimiques et Technologiques, 118 route de Narbonne, 31077 Toulouse cedex, France
³  CEMES 8011 du CNRS, 2 rue Jeanne Marvig, 31055 Toulouse, France
⁴  Laboratorio de Catalise e Materiais, Departamento de Engenharia Quimica, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias sin, 4200-465 Porto, Portugal

Abstract
Multi-walled carbon nanotubes (MWNT) and carbon nanospheres (NanoC) have been used as substrates for the deposition of platinum nanoparticles by Metal-Organic Chemical Vapor Deposition in a fluidized bed reactor starting from [ PtMe ₂(COD)] . On untreated graphitic substrates no platinum deposition was observed at 110°C, a temperature at which Pt can be deposited from the same precursor on SiO ₂. An explanation based on the lack of oxygen-containing anchoring groups for the grafting of the platinum precursor on such carbon supports is proposed. Similar results were obtained on highly orientated pyrolytic graphite. It is shown that an oxidative treatment of MWNT and NanoC with nitric acid allows to functionalize the carbon surface through the formation of -COOH groups, and that the carboxylic acid groups can act as anchoring sites for platinum nanoparticles deposition. The platinum mean particle size was found to be smaller in the case of Pt/MWNT than for Pt/NanoC.

© EDP Sciences 2002