Pt–Ni Bimetallic Catalysts with High Catalytic Activity for the Hydrogenation of Dibenzyltoluene

Abstract

Liquid organic hydrogen carriers (LOHCs) have attracted increasing attention in recent years for their hydrogen-storage potential; among them, dibenzyltoluene (DBT) is one of the most promising candidates. Supported Pt catalysts have been widely used for DBT hydrogenation, yet the high Pt loading required becomes a major cost barrier to its scale-up. Herein, we report an Al2O3-supported Pt–Ni bimetallic catalyst containing only 0.5 wt % Pt that, under mild conditions (120 °C, 2.5 MPa), delivers 100% DBT conversion with 99.4% selectivity. Comprehensive characterizations (transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), H2 temperature-programmed desorption (H2-TPD), and in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS)) reveal that the enhanced activity originates from (i) electron transfer from Pt species to Ni, which modifies the electronic structure of the Ni sites and strengthen the Ni–H bonds; (ii) the formation of smaller and highly dispersed Ni nanoparticles (NPs), promoted by Pt introduction; and (iii) suppressed desorption of reaction intermediates upon Pt incorporation, together with accelerated hydrogen spillover that facilitates the migration of active H* species and improves DBT conversion efficiency. Consequently, the catalyst maintains superior hydrogenation performance, offering a practical route toward low-cost DBT-based hydrogen storage.