From Inert to Catalytically Active Milling Media: Galvanostatic Coating for Direct Mechanocatalysis

The inert milling balls, commonly utilized in mechanochemical reactions, were coated with a layer of Pd and utilized as catalyst in the direct mechanocatalytic Suzuki reaction. With high yields (>80 %), the milling balls can be recycled multiple times in the absence of any solvents, ligands, catalyst-molecules and -powders, while utilizing as little as 0.8 mg of Pd per coated milling ball. The coating sequence, the support material, and the layer thickness were examined towards archiving high catalyst retention, low abrasion and high conversion. The approach was transferred to the coating of milling vessels revealing the interplay between catalytically available surface area and the mechanical energy impact in direct mechanocatalysis.

Automated summary

The inert milling balls coated with Pd were used as catalyst in the direct mechanocatalytic Suzuki reaction, achieving high yields (>80%) and recycling capabilities. The coating sequence, support material, and layer thickness were optimized for catalyst retention, abrasion resistance, and conversion. The approach was also applied to coating milling vessels, revealing the interplay between catalytically available surface area and mechanical energy impact in mechanocatalysis.