A Robust and Efficient Propane Dehydrogenation Catalyst from Unexpectedly Segregated Pt₂Mn Nanoparticles.

Area of Science:

• Catalysis Science and Engineering
• Materials Science
• Chemical Engineering

Background:

• Growing demand for propene in plastics production necessitates efficient propane dehydrogenation (PDH) catalysts.
• Shale gas availability makes PDH a key process, but catalysts face harsh regeneration conditions, limiting their industrial application.
• Developing robust and highly performing PDH catalysts is critical for sustainable chemical manufacturing.

Purpose of the Study:

• To synthesize and characterize a novel nanometric, bimetallic platinum-manganese (Pt-Mn) catalyst supported on silica.
• To evaluate the catalyst's performance and stability in propane dehydrogenation (PDH) reactions, particularly under demanding regeneration cycles.
• To elucidate the structure-activity relationship responsible for the catalyst's exceptional catalytic properties.

Main Methods:

• Preparation of a Pt-Mn/silica catalyst using surface organometallic chemistry and thermolytic molecular precursor approaches.
• Characterization of the material's structure, including Mn oxidation states and Pt-Mn particle segregation, using techniques like X-ray absorption spectroscopy and electron microscopy.
• Evaluation of catalytic performance in PDH reactions, assessing conversion, selectivity, deactivation rates, and robustness during regeneration.

Main Results:

• A nanometric Pt-Mn/silica catalyst was successfully synthesized, featuring MnII single sites and segregated Pt2Mn nanoparticles.
• The catalyst demonstrated high performance in PDH, with stable conversion (~37%) and selectivity (~98%) after repeated regeneration cycles.
• A low-loading Pt-Mn catalyst exhibited exceptional initial productivity (4523 gC/gPt h) and a very low deactivation rate (kd = 0.003 h-1).

Conclusions:

• The strong interaction between MnII-decorated silica support and segregated Pt2Mn particles is key to the catalyst's outstanding performance and robustness.
• The developed Pt-Mn catalyst offers a promising solution for efficient and stable propene production via PDH.
• This research advances the development of next-generation catalysts for the petrochemical industry.