This paper reviews the preparation, characterization and catalytic activity of carbon supported platinum catalysts. It contains published and unpublished results and emphasizes the most relevant aspects concerning the fundamentals of the preparation of metal/carbon catalysts in terms of precursor-support and metal-support interactions. A plenty of techniques are involved in this study, including transient techniques, XAFS, XRD, etc. The kind and degree of interaction is analyzed in both fresh and reduced catalysts. The variables under investigation are the ionic character of the platinum precursor used and the surface chemistry of the support. The properties of these catalysts are also discussed in terms of their catalytic activity in the CO₂ hydrogenation reaction. Furthermore, the selected reaction is sensitive to the structure of the catalysts, what allows a deeper analysis of the catalysts structure under different conditions.