Cu0and Pd0loaded Organo-Bentonites as Sponge-like Matrices for Hydrogen Reversible Capture at Ambient Conditions

Abstract

Sponge-like gluco- and thioglycerol-organo-bentonite hosting Cu0 and Pd0 subnanoparticles with high affinity towards hydrogen were synthesized through an unprecedented procedure involving a chemical grafting of (3-azidopropyl)triethoxysilane, followed by Cu-catalyzed azide-alkyne cycloaddition with propargyl glucoside or triallyl propargyl pentaerythritol. Further, thioglycerol groups were attached to the alkene groups by photolysis (TEC reaction). This resulted in a structure swelling, but further Cu0 or Pd0 nanoparticle incorporation produced a compaction due to strong O:metal and S:metal interactions that improve metal stabilization and prevent re-aggregation. Such a structure favored hydrogen capture via physical condensation with easy release at nearly ambient temperature at the expense of hydrogen dissolution in the metal bulk. This innovative concept opens new prospects for obtaining low cost clay-based matrices for a truly reversible capture of hydrogen.