The results of a series of adsorption and coadsorption measurements using (+/-)- 1-(1-naphthyl) ethylamine (NEA), methyl pyruvate, ester-deuterated methyl pyruvate, methyl naphthalene and 2,3-butanedione on Pt(111) are presented. Coadsorption of NEA stabilizes a molecularly adsorbed state of methyl pyruvate. The latter state undergoes thermal decomposition to yield a methane desorption peak centred at 320 K. Experiments performed using ester-deuterated methyl pyruvate show that the methane desorption results from the decomposition of the acetyl moiety of the alpha-ketoester. A stabilizing interaction is not observed for coadsorbed methyl naphthalene and methyl pyruvate, presumably due to the absence of an amine group. The study provides further evidence for the existence of a 1: 1 methyl pyruvate - 1-( 1- naphthyl) ethylamine docking complex on Pt( 111) under ultrahigh vacuum conditions.