In a study published in ACS Catalysis, Associate Prof. LIU Hongyang's team from Institute of Metal Research (IMR) of the Chinese Academy of Sciences reported that a Tin assisted fully exposed Pt clusters are fabricated on the core-shell nanodiamond@graphene (ND@G) hybrid support for dehydrogenation reaction.

Light olefins are important building blocks for the synthesis of polymers and other value-added chemicals. Direct dehydrogenation (DDH) of light alkane is a typically industrial process for the production of olefin. As an endothermic reaction, it requires high temperatures to obtain satisfactory conversion rates and olefin yields. However, high reaction temperatures could lead to serious catalyst deactivation by sintering of active sites and coking.

To date, Pt₃Sn alloy catalyst (Pt₃Sn/Al₂O₃) is recognized as one of the best catalysts for this reaction. However, rapid deactivation is still a main problem because the sintering of Pt₃Sn nanoparticles (NPs) is unavoidable during dehydrogengfation process, and only the surface Pt atoms in Pt₃Sn NPs can participate in the catalytic reaction.

Associate Prof. LIU's team have been dedicated to develop new nano-carbon material supported metal catalysts. They have been focusing on a better dispersed and more stabilized Pt-based catalyst which is pivotal for the DDH of alkanes.

In this study, researchers firstly reported the Pt-Sn catalyst with unique Pt species, fully exposed Pt clusters anchoring over the ND@G support (a-PtSn/ND@G).

Using aberration-corrected transmission electron microscopy and X-ray absorption fine structure (XAFS) spectra, they constructed the structures of three Pt atoms anchored on ND@G. The as-synthesized a-PtSn/ND@G catalyst showed excellent catalytic performance in DDH of n-butane at a relatively low temperature.

Then, they built the catalyst structures and studied the reaction mechanism by quantum chemistry simulation at the density functional theory (DFT) level. The atomically dispersed Pt clusters has guaranteed a full metal availability to the reactants, a high thermal stability as well as an optimized adsorption/desorption behavior.

This study paves the way for rational design of highly activity catalysts for dehydrogenation.

The Journal cover (Image by ACS Catalysis)