Using first-principles modeling to investigate dehydrogenation of perhydro-dibenzyltoluene on Pt/M surface alloys (M = Fe, Ni, and Cu)

Abstract

Understanding a dehydrogenation process for a liquid organic hydrogen carrier on catalysts is vital for providing insight into the development of efficient catalysts. This study examined the hydrogen release from perhydro-dibenzyltoluene (H18-DBT) over Pt-doped Pt/M surface alloys with two different Pt surface concentrations: Pt33%/M and Pt67%/M (M = Fe(1 0 0), Ni(1 1 1), and Cu(1 1 1)). The influence of the Pt surface concentrations of each catalyst on the hydrogen release from DBT was analyzed. The effects of the Pt surface concentration differed according to the host catalyst. The dehydrogenation reaction became favorable over Pt67%/Fe(1 0 0) surface with increasing Pt surface concentration. By contrast, dehydrogenation on Pt33%/Ni(1 1 1) and Pt33%/Cu(1 1 1) was more favorable at relatively lower Pt surface concentrations. In addition, the dehydrogenation reaction was tuned by an external electric field provided to the catalyst. The rate-determining step of a dehydrogenation process was the step that first releases hydrogen in the middle ring of H18-DBT over the Pt/M alloys investigated. Overall, the hydrogen adsorption energy was found to be a valid descriptor for assessing promising dehydrogenation catalysts.