Abstract
Developing highly efficient and reversible hydrogenation-dehydrogenation catalysts shows great promise for hydrogen storage technologies with highly desirable economic and ecological benefits. Herein, we show that reaction sites consisting of single Pt atoms and neighboring oxygen vacancies (VO) can be prepared on CeO2 (Pt1/CeO2) with unique catalytic properties for the reversible dehydrogenation and rehydrogenation of large molecules such as cyclohexane and methylcyclohexane. Specifically, we find that the dehydrogenation rate of cyclohexane and methylcyclohexane on such sites can reach values above 32,000 molH2 molPt−1 h−1, which is 309 times higher than that of conventional supported Pt nanoparticles. Combining of DRIFTS, AP-XPS, EXAFS, and DFT calculations, we show that the Pt1/CeO2 catalyst exhibits a super-synergistic effect between the catalytic Pt atom and its support, involving redox coupling between Pt and Ce ions, enabling adsorption, activation and reaction of large molecules with sufficient versatility to drive abstraction/addition of hydrogen without requiring multiple reaction sites.
Highlights
Developing highly efficient and reversible hydrogenation-dehydrogenation catalysts shows great promise for hydrogen storage technologies with highly desirable economic and ecological benefits
Reversible Liquid organic hydrogen carriers (LOHCs) systems are always composed of pairs of hydrogen-poor and hydrogenrich organic compounds that store hydrogen by hydrogenation and dehydrogenation[25], which has a high potential for mobile applications[26]
The Pt1/CeO2 catalyst was fabricated by a modified ascorbic acid (AA)-assisted reduction method, described in detail in the methods section[32]
Summary
Preparation and characterization of isolated single Pt sites on CeO2 (Pt1/CeO2). The Pt1/CeO2 catalyst was fabricated by a modified ascorbic acid (AA)-assisted reduction method, described in detail in the methods section[32]. In more detail, compared with the PtO2 reference, there is not an obvious white line shift of Pt1/ CeO2 due to the low Pt concentration on the surface and detector limitation, the lower energy shoulder (Fig. 1) indicates that the Pt oxidation state in Pt1/CeO2 is lower than +434, in agreement with the ambient-pressure X-ray photoelectron spectroscopy (APXPS) results. These low oxidation state Pt species are critical to our proposed mechanism below, especially in the initial stage of the reaction.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
