Group 10 Metal Allyl Amidinates: A Family of Readily Accessible and Stable Molecular Precursors to Generate Supported Nanoparticles

Abstract

The synthesis of well-defined materials as model systems for catalysis and related fields is an important pillar in the understanding of catalytic processes at a molecular level. Various approaches employing organometallic precursors have been developed and established to make monodispersed supported nanoparticles, nanocrystals, and films. Using rational design principles, a new family of precursors based on group 10 metals suitable for the generation of small and monodispersed nanoparticles on metal oxides has been developed. Particle formation on SiO 2 and Al 2 O 3 supports is demonstrated, as well as the potential in the synthesis of bimetallic catalyst materials, exemplified by a PdGa/SiO 2 system capable of hydrogenation of CO 2 to methanol. In addition to surface organometallic chemistry (SOMC), it is envisioned that these precursors could also be employed in related applications, such as atomic layer deposition, due to their inherent volatility and relative thermal stability.

Reactivity Switch of Platinum with Gallium: From Reverse Water Gas Shift to Methanol Synthesis

“…An analogous system was developed earlier in the context of propane dehydrogenation . Here, we selected Pt allyl-( N , N ′-diisopropyl)­acetamidinate, Pt­(η 3 -allyl)­(DIA), a siloxide-free molecular precursor, in order to avoid the formation of additional interfaces from the decomposition of the organic ligands . The synthesis consists of a two-step process, involving grafting of the molecular Pt precursor on silica decorated with isolated Ga III sites (Ga III @SiO 2 , 1.83 wt % corresponding to ca.…”

Implications of Ga promotion and metal–oxide interface from tailored PtGa propane dehydrogenation catalysts supported on carbon

“…Two different classes of organometallic precursors – amidinate/alkyl vs. siloxide – were used as a strategy to prepare a set of Pt and PtGa based catalysts with a tailored interface on carbon. On the one hand, molecular precursors such as [GaMes 3 ] 16 and platinum allyl-( N-N ′-diisopropyl)acetamidinate ([PtAMD]) 17 are used for the preparation of carbon-supported Pt and PtGa nanoparticles, while thermolytic molecular siloxide precursors 10 [Ga(OSi(O t Bu 3 ) 3 ) 3 (THF)] 18 and [Pt(OSi(O t Bu 3 ) 3 ) 2 (COD)] 19 are used to prepare the corresponding supported Pt and PtGa nanoparticles with an oxide interface (Fig. 1B).…”