Pausing a stir: heterogeneous catalysis in "dry water"

Benjamin O. Carter, Dave J. Adams, Andrew I. Cooper
2010 Green Chemistry  
Experimental Materials The hydrophobic silica nanoparticles (H18) were kindly supplied by Wacker Chemie. Maleic and succinic acids (certified purities ≥99%), ruthenium catalyst (5 wt% loading on alumina, reduced) and deuterium oxide (for 1 H-NMR, 99.9 atom % D) were purchased from Sigma-Aldrich. Hydrogen gas (high purity, 99.995% minimum) was purchased from BOC Gases. The morphologies of the various dry water (DW) samples were observed using an Olympus CX41RF Microscope, fitted with a Linkam
more » ... ed with a Linkam FDCS 196 variable temperature stage. Photographs were taken with an Olympus C-5060 digital camera. Dry water reaction mixture preparation Maleic acid (0.9577 g) was dissolved in deionised water (110 mL, 0.075 M), before pouring into a blender (Vitamix 2-Speed, 1.4 L polycarbonate jug). Hydrophobic silica (5.79 g, 5 wt% with respect to water) and ruthenium catalyst (0.1790 g, 1.625 gL -1 ) were mixed by hand until homogeneous, and then added to the blender jug. Mixing was carried out at the higher speed setting (37,000 rpm) for 3x 30s bursts, with >1min periods between bursts to minimise droplet dissociation due to heat generated while mixing. The resulting pale grey powder could then be transferred between vessels by pouring.
doi:10.1039/b922508k fatcat:yfelzohudjgh5m7ugnsf3umrna