Full utilization of noble metals by atom abstraction for propane dehydrogenation.

Maximizing atomic utilization of noble metals is crucial for efficient industrial catalysis. We demonstrate that minimal platinum (Pt) loading for propane dehydrogenation (PDH) can be achieved through atom abstraction. At low loadings of Pt with copper (Cu), reduction over silica or other oxide supports formed nanoparticles (NPs) with Pt mainly dispersed in the bulk. Addition of tin (Sn) to the alloy led to formation of surface Pt1Sn1 dimers. The larger atomic radius of Sn compared with Cu drove it to the surface, and its stronger interactions with Pt abstracted Pt from the bulk. Single metallic Pt atoms were stabilized on fully open surfaces, resulting in nearly 100% surface exposure. This configuration reduced Pt usage by one order of magnitude for propane dehydrogenation and improved catalytic stability. Editor's summary: Nanoparticles of copper doped with tin and platinum disperse nearly all of the platinum at the surface as tin-platinum dimers. Sun et al. found that at low loadings, platinum was dispersed mainly in the bulk of copper nanoparticles, but tin segregation and strong tin-platinum interactions drove platinum to the surface. These silica- and zeolite-supported catalysts were highly active for propane dehydrogenation. —Phil Szuromi INTRODUCTION: Catalysts accelerate chemical reactions and are central to modern energy transformation and chemical manufacturing. They convert raw, low-value resources into fuels, plastics, and countless everyday products. Noble metals such as platinum (Pt) are among the most active catalysts, yet their scarcity and high cost make the efficient utilization of every single atom critical. This is especially true for demanding industrial processes such as propane dehydrogenation (PDH), which produces propylene, a key building block for numerous chemicals and plastics. RATIONALE: Most current catalysts rely on alloy nanoparticles (NPs), in which a high number of noble metal atoms are buried within the particle interior. As a result, only a fraction of these costly atoms actively participate in catalysis, limiting efficiency. Single-atom catalysts offer a promising alternative as they in principle allow every atom to contribute. However, existing methods often produce atoms that are partially oxidized or confined within micropores, restricting accessibility. Such isolated atoms also tend to aggregate under high-temperature reducing conditions, compromising stability and performance. Addressing these challenges requires a broadly applicable strategy to maintain fully exposed, metallic noble atoms on openly accessible surfaces. This would maximize atomic utilization, reduce noble metal consumption and cost, and ensure durable performance under harsh conditions. We introduce an atom abstraction strategy in which a promoter metal on the surface of NPs abstracts noble atoms from the particle interior to the exterior. This enables the formation of isolated, fully exposed metallic active sites that remain robust in demanding catalytic environments. RESULTS: We prepared copper (Cu) NPs supported on silica (SiO2), with atomically dispersed Pt-Sn motifs at the surface. The tin (Sn) atoms, larger than Cu and strongly attracted to Pt, pulled Pt from the interior of the Cu NPs to the surface, forming stable Pt1Sn1 pairs and leaving nearly all Pt atoms fully exposed, even at ultralow loadings (0.01 to 0.03 wt %). Careful analysis confirmed that Pt, Sn, and Cu remained metallic, with Sn donating electrons that made Pt even more selective. When tested in PDH, this cost-effective catalyst produced propylene at a rate 12 times higher than that of the commercial PtSn catalyst while using only one-tenth the Pt. Even at identical Pt loadings, the PtSnCu catalyst delivered two to three times higher activity under the same conditions. The material also exhibited a long lifetime, deactivating two to three times slower and retaining more than 90% of its activity after repeated regeneration cycles. Further trials with other combinations of noble and promoter metals suggest that this atom abstraction approach can be applied broadly. CONCLUSION: Atom abstraction, driven by the atomic size difference between the promoter and host metals as well as strong promoter–noble metal interactions, provides a straightforward route to create fully exposed, metallic single-atom active sites. This strategy enables nearly full utilization of noble metals, reducing their demand by up to one order of magnitude while maintaining high activity and stability under the industrial high-temperature conditions of PDH. Our tests show that this approach works with a variety of metal combinations, offering a versatile and practical path toward more efficient, durable, and sustainable catalysts. The PtSnCu catalyst, fabricated through an atom abstraction strategy, achieves nearly full Pt exposure. This leads to superior propylene formation rates, increased operational lifetime, and substantially reduced catalyst costs relative to conventional PtSn and PtCu single-atom alloy (SAA) catalysts, demonstrating a breakthrough in noble metal utilization for industrial catalysis. [ABSTRACT FROM AUTHOR]