Controlled Nanopore Sizes in Supraparticle Supports for Enhanced Propane Dehydrogenation with GaPt SCALMS Catalysts

The efficient immobilization of GaPt liquid metal alloy droplets onto tailored supports improves catalytic performance by preventing coalescence and subsequent loss of active surface area. Herein, we use tailored supraparticle (SP) supports with controlled nanopores to systematically study the influence of pore sizes on the catalytic stability of GaPt supported catalytically active liquid metal solution (SCALMS) in propane dehydrogenation (PDH). Initially, GaPt droplets were prepared via an atom-efficient and scalable ultrasonication method with recycling loops to yield droplets <300 nm. Subsequently, these droplets were immobilized onto SiO₂-based SPs with controlled pore sizes ranging from 45 to 320 nm. Catalytic evaluations in PDH revealed that GaPt immobilized on SPs with larger pores demonstrated superior stability over 15 h time-on-stream evidenced by reduced deactivation rates from 0.046 to 0.026 h^-1. Nanocomputed tomography and identical location SEM confirmed the successful immobilization of GaPt droplets within the interstitial sites formed by the primary particles constituting the SPs. These remained unchanged before and after the catalytic reaction, demonstrating efficient coalescence prevention. Our findings underscore the importance of support pore size engineering for improving the stability of GaPt SCALMS catalysts and highlight, particularly, the high potential of using SPs in this context.