CH4 dehydrogenation and H2 formation on a Pt(100) surface: an insight from the reactive molecular dynamics simulations

Abstract

Many research initiatives are now dedicated to efficient methods of COx-free H₂ production. In this study, we investigated the process of CH₄ molecule dissociation on a Pt(100) surface using ReaxFF-based molecular dynamics simulations. On the Pt(100) surface, we observed that H atoms dissociated one by one from the CH₄ molecule. The C atoms then entered the subsurface and formed carbon chains with other carbon atoms or fragments of CH₃, CH₂, and CH. The formation of carbon chains degrades the surface structure of the Pt. The Pt atoms that emerged on the surface subsequently became extremely active and formed bonds with the dissociated H atoms before being liberated from the substrate. HPt, H₂Pt, H₃Pt, H₃Pt₂, H₄Pt₂, CH₄Pt₂, and CH₅Pt are examples of molecules formed from the Pt, H, and C atoms. During the simulation process, approximately 25% of all the H atoms progressively formed H₂ molecules. The results of our reactive molecular dynamics simulations confirmed that the Pt(100) surface is a possible catalyst for the synthesis of H₂ molecules.