Pd/SBA-15 nanocomposite: Synthesis, structure and catalytic properties in Heck reactions

Pd nanoparticles supported in mesoporous silica SBA-15 (or Pd/SBA-15 nanocomposites) were prepared by ion-exchange with cationic Pd precursor in an alkaline solution on an uncalcined silica. The high Pd loading in these nanocomposites can be achieved up to 5.21 wt.% by adjusting the pH value of the solution. The surface area and the pore volume decrease with increasing Pd loading. The Pd nanoparticles equal to or smaller than 6 nm in size in the nanocomposites are distributed in the channels of the mesoporous SBA-15. The Pd/SBA-15 nanocomposites exhibit excellent catalytic activities and high reuse ability in air for the Heck carbon–carbon coupling reactions.

Graphical abstractThe Pd/SBA-15 nanocomposite was synthesized via ion-exchange on non-calcined silica. The high Pd loading in these nanocomposites can be achieved up to 5.21 wt.% (shown below) by adjusting the pH value of the solution. The Pd/SBA-15 nanocomposites exhibit excellent catalytic activities in air for the Heck coupling reactions. Further, they also showed high reuse ability for the Heck reaction.Figure optionsDownload full-size imageDownload as PowerPoint slideResearch Highlights► We prepared highly dispersed and uniform Pd nanoparticles supported in mesoporous silica SBA-15 by ion-exchange with cationic Pd precursor in an alkaline solution on an uncalcined silica. ► The high Pd loading in these nanocomposites can be achieved up to 5.21 wt.% by adjusting the pH value of the solution. ► Using this method higher than 65% of the Pd precursor in the solution was incorporated into the mesoporous SBA-15. ► The Pd nanoparticles equal to or smaller than 6 nm in size in the nanocomposites are distributed in the channels of the mesoporous SBA-15. ► The Pd/SBA-15 nanocomposites exhibit excellent catalytic activities and high reuse ability in air for the Heck carbon-carbon coupling reactions.