Synthesis of Supported Planar Iron Oxide Nanoparticles and Their Chemo- and Stereoselectivity for Hydrogenation of Alkynes

Abstract

Nature uses enzymes to dissociate and transfer H 2 by combining Fe 2+ and H + acceptor/donor catalytic active sites. Following a biomimetic approach, it is reported here that very small planar Fe 2,3+ oxide nanoparticles (2.0 ± 0.5 nm) supported on slightly acidic inorganic oxides (nanocrystalline TiO 2 , ZrO 2 , ZnO) act as bifunctional catalysts to dissociate and transfer H 2 to alkynes chemo-and stereoselectively. This catalyst is synthesized by oxidative dispersion of Fe 0 nanoparticles at the isoelectronic point of the support. The resulting Fe 2+,3+ solid catalyzes not only, in batch, the semihydrogenation of different alkynes with good yields but also the removal of acetylene from ethylene streams with >99.9% conversion and selectivity. These efficient and robust non-noble-metal catalysts, alternative to existing industrial technologies based on Pd, constitute a step forward toward the design of fully sustainable and nontoxic selective hydrogenation solid catalysts.

Selective ensembles in supported palladium sulfide nanoparticles for alkyne semi-hydrogenation

“…However, sulfur poisoning is much more effective as very small nanoparticles with a high surface/volume ratio can be used instead of the large nanoparticles required for the PdPb catalyst. The need for facile hydrogen activation limits the practical relevance of oxides and other metals (Ag, Au) 19 , 26 , 34 , 35 , 66 . This is not the case in Pd x S, intermetallics, ligand-modified nanoparticles, and single-atom catalysts due to the intrinsic ability of Pd to activate H 2 .…”

“…However, the recent disruptive legislations restricting the use of hazardous compounds have steered the innovation and creativity of scientists towards the development of sustainable alternatives. This has enabled the incorporation of new families of hydrogenation catalysts based on: (i) alternative metals 1 , 2 , 7 , 9 , 10 , 30 , (ii) alloy and intermetallic compounds 8 , 11 – 16 , 18 – 21 , (iii) ligand-modified nanoparticles 6 , 17 , 22 , 25 , (iv) transition metal oxides 26 , 27 , 34 , 35 , and (v) supported single atoms 24 , 31 , 32 . While these share better ensemble definition than unmodified Pd, intrinsic drawbacks like instability against high pressure induced segregation for intermetallics 44 – 46 , accessibility constraints in ligand-modified and single atom catalysts 31 , 47 , and poor H 2 activation on oxides 48 have been identified.…”

Semihydrogenation of Acetylene on Indium Oxide: Proposed Single‐Ensemble Catalysis

“…Two directions have shown significant promise: 1) targeting the improved design of noble‐metal‐based catalysts by reducing the size of the metal ensemble through development of ligand‐modified systems, bimetallic compounds, and single‐atoms heterogeneous catalysts, and 2) exploiting the untapped potential of metal oxides . In this context, cerium oxide and supported iron oxide have emerged as highly selective catalysts for the semihydrogenation of acetylene, a reaction integral to the purification of olefin streams for downstream polymerization processes . Detailed mechanistic studies of the former have unraveled the role of the surface Ce−O pairs in activating molecular hydrogen (H 2 ) and stabilizing the various reaction intermediates .…”

The effect of iron oxide nanoparticles on the mechanical relaxation of magnetic polymer hybrid films composed of a polystyrene matrix, a fractional calculus approach

“…The addition of IONPs into a PS matrix produces a synergy among them, such that the obtained MPHF responds to an external magnetic field with fast reaction and contactless control . Additional applications could also be obtained for MPHFs considering that the magnetic properties of IONPs are very important due to their potential integration into a broad range of technological applications, extending from magnetic fluids, catalysis, ultrahigh‐density magnetic storage media, biotechnology and biomedicine, and magnetic resonance imaging …”