Process for preparing a carboxylic acid

A process for preparing carboxylic acid comprising a step of placing at least one vicinal diol or at least one vicinal polyol in contact with an atmosphere comprising oxygen, a catalyst and in the absence of additional solvent, the catalyst having the formula I below:

• [AlnSimOpMq][A]r (I)
• wherein:
• n, m and q are natural integers (), which may be identical or different, chosen, independently of each other, such that n, m and q may simultaneously be equal to 0;
• p is a nonzero natural integer (*);
• r is zero or 1;
• M corresponds to at least one chemical element chosen from zirconium, tungsten, titanium and rare-earth metals, and
• A corresponds to at least one chemical element chosen from alkaline-earth metals, alkali metals, rare-earth metals and titanium;
• wherein the catalyst is one of the following catalysts:
• Al2O3, SiO2, TiO2, and ZrO2.