Probing the origin of in situ generated nanoparticles as sustainable oxidation catalysts

Abstract

A novel method for the in situ generation of catalytically active small metal nanoparticles, by anion extrusion on a parent porous copper chloropyrophosphate framework, have been developed to generate gold, platinum and palladium 10 nanoparticles for sustainable catalytic oxidations using molecular oxygen as the oxidant. Transmission electron microscopy coupled with detailed structural and physicochemical characterisation, in combination with in-depth kinetic analysis have afforded profound insights into the 15 nature of the active site for facilitating structure-property correlations.

Predictive design of engineered multifunctional solid catalysts

“…Whilst such a strategy has been highly effective at the laboratory scale, industrial scale-up for bulk chemistry applications has proved expensive and often difficult to manipulate, due to the delicate air-sensitive nature of the reagents and precursors. Recently in situ methods of generating metal nanoparticles have been developed 55 through the addition of an anionic metal-chloride precursor into the pores of a copper chloropyrophosphate framework. Using this approach, precursors of Pt, Pd or Au were extruded from the pores of the support, to generate isolated metal nanoparticles for the aerobic oxidation of benzyl alcohol (Table 3).…”

Elucidating Structure–Property Relationships in the Design of Metal Nanoparticle Catalysts for the Activation of Molecular Oxygen

“…Monometallic (Au, Pt, Pd) and bimetallic NPs have been successfully employed in the selective oxidation of alcohols 1 including glycerol, 2 cinnamyl alcohol, 3 crotyl alcohol 4,5 and benzyl alcohol, 6,7 to name but a few. Prodi- 35 gious design of bimetallic equivalents has recently demonstrated their propensity for C-H activation, particularly in the oxidation of aromatics.…”

“…5 nm) by extrusion of MClx precursor complex anions (M = Au, Pt or Pd) from a crystalline microporous copper chlorophosphate framework ( Figure 1). 7 The framework is of Cu-2 topology 37 and has flexible anion-exchange properties. 38 In this 35 article, we rationalize and demonstrate the efficacy of our design strategy for the in situ generation of nanoparticles within a microporous host architecture, wherein the porous framework can be employed synergistically as an active species, and not just as a heterogeneous support, 40 thereby affording exciting prospects for bifunctional catalysis.…”

Iridium–Bismuth Cluster Complexes Yield Bimetallic Nano-Catalysts for the Direct Oxidation of 3-Picoline to Niacin

“…6 The precise controlled synthesis of catalytically-active metal nanoparticles has been of great interest in recent years, 7,8 with the ever-expanding target of creating discrete single-sites. With a view to achieving this goal, a number of elegant strategies using inorganic porous supports, [9][10][11] polymer-stabilized matrices 12 and framework extrusion processes 13 have been developed. Despite the intrinsic merits of these approaches, [9][10][11][12][13] the desire to modulate catalytic activity and selectivity at the nanoscale, through the adroit choice of appropriate metal combinations and their concomitant oxophilic analogues, for generating uniform, discrete, well-defined, multifunctional single-sites, remains a challenging prospect.…”