Catalytic insights into perhydro-benzyltoluene dehydrogenation: Probing surface characteristics revealed by DRIFTS study

Abstract

The enhancement of dehydrogenation activity in liquid organic hydrogen carriers (LOHC), such as perhydrobenzyltoluene (H12 -BT), has been attributed to the addition of various promoters and support modifications into platinum (Pt) -based heterogeneous catalysts. Comprehensive understanding of surface sites predominantly catalyzing the dehydrogenation process is crucial for further enhancing catalytic performance. In this contribution, an in-depth quantitative CO diffuse reflectance infrared Fourier transform spectroscopy (CO -DRIFTS) study on Pt -based catalysts with varying contents of sulfur, known to be effective in dehydrogenation reactions, is performed to unveil the active sites involved in the H12 -BT dehydrogenation. Furthermore, while challenges associated with the adsorption step of reactants and products potentially deteriorate catalytic activity, these processes remain open questions for H12 -BT dehydrogenation. To shed light on these aspects, we conducted in situ DRIFTS experiments utilizing H12 -BT and H0 -BT, its dehydrogenated counterpart, to determine the adsorption strength between these molecules and the different catalyst surfaces, influenced by the electrondeficiency effect due to the addition of sulfur. Additionally, our study investigates the correlation between sulfur -induced catalyst surface characteristics and the formation of methane through the demethylation process.