PtRu nanoparticle catalysts with adjustable electronic environments for efficient low-temperature dehydrogenation of...

Modulating the electronic structure of active catalytic species to optimise the adsorption and activation steps of reactants is crucial for achieving efficient and stable dehydrogenation of liquid organic hydrogen carriers. In this study, a uniformly dispersed PtRu nanoalloy catalyst (PtRu/Al₂O₃) was successfully prepared on Al₂O₃ sheets through a process strategy combining wet chemical impregnation, low-temperature pre-reduction, and high-temperature annealing. The degree of Pt electron enrichment induced by Ru modification can be precisely controlled by adjusting Pt/Ru ratio, and this enrichment level is positively correlated with Ru coverage. The PtRu alloy with moderate electronic enrichment significantly lowers both the adsorption energy and the CH bond activation energy at key active sites. This facilitated the rapid desorption and transfer of the products, ultimately determining the overall dehydrogenation efficiency. Catalytic tests show that the Pt₂Ru₁/Al₂O₃ catalyst achieves a single-ring cycloalkane dehydrogenation conversion rate of over 99% at 200 °C. Even for decalin, the conversion rate reaches 69% at 230 °C. Furthermore, its apparent activation energy (68.4 kJ/mol) was lower than that of conventional Pt/Al₂O₃, demonstrating the kinetic advantages attributed to the electronic effects in Pt₂Ru₁/Al₂O_3. Both experimental results and theoretical analyses confirm that intermetallic electronic interactions contribute to the enhanced hydrogen production rates, and further elucidate the charge transfer mechanism within the PtRu alloy.