Pt monolayers with high catalytic activity were deposited onto carbon nanotube mattes by the chemical displacement of Cu monolayers on CNTs produced using an underpotential electro-deposition method. The electrochemical surface modification of graphitic CNT surface by fluorinated benzoic acid was critical to coordinate Cu ions resulting in uniform Cu monolayer formation. For MeOH fuel cell applications, the mass activity of Pt monolayer reached 2711 A g⁻¹ at a scan rate of 20 mV s⁻¹ and in a solution of 1 M CH₃OH/0.5 M H₂SO₄. This is a 13 fold improvement than that of the ∼10 nm thick Pt film coated on MWCNTs. Besides the high mass activity that is needed for the widespread used of rare catalytic metals in fuel cell applications, the Pt monolayer coated on buckypaper has several other advantages such as low cost, high surface area, flexibility, mechanical robust and enhanced mass transport.