Oxidative deamination is part of the metabolic pathways of amino acid oxidase and glutamate dehydrogenase enzymes, and enables obtaining α-keto acid from amino compound with ammonia as a by-product. This work presents the utilization of Pt-based catalyst composed of small platinum nanoparticles supported on industrial silica support (Pt/SiO2). This nanozyme was tested in the oxidative deamination reaction of two amino compounds: 5-hydroxymethylfurfurylamine (HMFA) to 5-hydroxymethylfurfural (HMF) and glutamic acid (GA) to α-ketoglutaric acid (KGA). This paper outlines the use of Pt nanozymes with deaminase-like activity. We showed the ability of this nanozymes to be selective and active in liquid phase oxidative deamination of HMFA and glutamic acid in a 6 to 9 pH range at 60°C under atmospheric pressure. Pt/SiO2 nanozyme actually plays as a deaminase mimic with high HMFA conversion (60%) and cumulative yield to the corresponding desaminated keto compounds (67%).