Platinum clusters with precise numbers of atoms for preparative-scale catalysis

Abstract

Subnanometer noble metal clusters have enormous potential, mainly for catalytic applications. Because a difference of only one atom may cause significant changes in their reactivity, a preparation method with atomic-level precision is essential. Although such a precision with enough scalability has been achieved by gas-phase synthesis, large-scale preparation is still at the frontier, hampering practical applications. We now show the atom-precise and fully scalable synthesis of platinum clusters on a milligram scale from tiara-like platinum complexes with various ring numbers (n = 5–13). Low-temperature calcination of the complexes on a carbon support under hydrogen stream affords monodispersed platinum clusters, whose atomicity is equivalent to that of the precursor complex. One of the clusters (Pt10) exhibits high catalytic activity in the hydrogenation of styrene compared to that of the other clusters. This method opens an avenue for the application of these clusters to preparative-scale catalysis.

Confining Sub‐Nanometer Pt Clusters in Hollow Mesoporous Carbon Spheres for Boosting Hydrogen Evolution Activity

“…As the annealing temperature increases, the binding energy of Pt 4f 7/2 moves toward lower binding energy. Deconvolution of the spectrum gives a new peak with a binding energy of 71.6 eV, which is in line with the reported Pt 12 clusters produced by dendrimer‐reactor and [Pt(µ‐SC 8 H 17 ) 2 ] 12 . Thus, increasing the annealing temperature simultaneously eliminates thiol ligands and reduces Pt 2+ to metallic Pt 0 .…”

“…Pt 5 (GS) 10 clusters were first synthesized according to a modified method (see the Supporting Information for details) . The molecular purity of Pt 5 (GS) 10 has been examined by ultraviolet–visible (UV–vis) spectroscopy and matrix‐assisted laser desorption ionization time‐of‐flight mass spectrometry (MALDI‐TOF‐MS) .…”

“…Two peaks with binding energies of 72.5 and 75.8 eV correspond to the Pt 4f 7/2 and Pt 4f 5/2 of Pt 2+ , respectively. Such Pt 2+ species in the Pt 5 (GS) 10 clusters could be adopted to selectively produce zero‐valent Pt under hydrogen gas stream and appropriate calcination condition (Figure , Step III) . The thermal stability of the Pt 5 (GS) 10 clusters was investigated by TGA to establish appropriate calcination conditions (Figure S5b, Supporting Information).…”

The Structure of Sub‐nm Platinum Clusters at Elevated Temperatures

“…Nanoparticles and clusters of Pt are used as catalysts in numerous chemical reactions, such as oxidative dehydrogenation of propane, chemical conversion of methane, styrene hydrogenation, electrooxidation of CO, hydrogen evolution reaction, and catalytic conversion of car exhaust. The catalytic activity of small Pt clusters increases with decreasing cluster size due to the large fraction of low‐coordinated surface atoms . Therefore, research has aimed at understanding structure and properties of single site catalysts of sub‐nm Pt clusters …”

“…The catalytic activity of small Pt clusters increases with decreasing cluster size due to the large fraction of low‐coordinated surface atoms . Therefore, research has aimed at understanding structure and properties of single site catalysts of sub‐nm Pt clusters …”