Designing Pt-based subsurface alloy catalysts for the dehydrogenation of perhydro-dibenzyltoluene: A first-principles study

Abstract

Designing effective dehydrogenation catalysts for liquid organic hydrogen carriers is essential to the release and transport of hydrogen. The hydrogen release of perhydro-dibenzyltoluene using Pt-based subsurface alloys (Pt/M/Pt(1 1 1), where M = Pd, Cu, or Ni) and the effect of the applied biaxial strain on dehydrogenation performance of Pt/M/Pt(1 1 1) were systematically investigated. The doping of M atoms onto Pt/M/Pt(1 1 1) and strained Pt/M/Pt(1 1 1) could effectively tune the electronic properties of the Pt atoms, thus eventually affecting the hydrogen adsorption strength. The rate-determining step (RDS) of the dehydrogenation process on surfaces of Pt(1 1 1), Pt/M/Pt(1 1 1), strained Pt(1 1 1), and strained Pt/M/Pt(1 1 1) was identical: the first step of dehydrogenation in the middle ring of perhydro-dibenzyltoluene. The doping of the M atoms and application of tensile strain promoted dehydrogenation. Furthermore, it was revealed that d-band centers and reaction energies of the RDS correlated with the hydrogen adsorption energy, suggesting that hydrogen adsorption strength is a practical descriptor of dehydrogenation activity.