Inspired by the recent surface experimental results that the monatomic Pt catalysts has more excellent hydrogen production that Cu(111) surface, the mechanism of decomposition of formic acid on Cu(111) and single atom Pt-1/Cu(111) surface was studied by periodic density functional theory calculations in the present work. The results show that the formic acid tends to undergo dehydrogenation on both surfaces to obtain the hydrogen product of the target product, and the selectivity and catalytic activity of Pt-1/Cu (111) surface for formic acid dehydrogenation are better. The reason is that the single atom Pt-1/Cu(111) catalyst reduces the reaction energy barrier (i.e., HCOO -> CO2 + H) of the critical step of the dehydrogenation reaction due to the fact that the single atom Pt-1/Cu(111) catalyst binds formate weakly compared to that of Cu (111) one. Moreover, it was found that the Pt-1/Cu (111) binds CO more strongly than that of Cu (111) one and thus leading to the difficult for the formation of CO. These two factors would make the single Pt atom catalyst had the high selectivity for the H-2 production. It is hoped that the present work may help people to design the efficient H-2 production from HCOOH decomposition by reduce the surface binding strength of HCOO species, for example, using the low coordination number active site like single atom or other related catalytic system. (C) 2017 Elsevier B.V. All rights reserved.