Metallic Iron Nanocatalysts for the Selective Acetylene Hydrogenation under Industrial Front-End Conditions

Abstract

The need for nontoxic, cheap, earth-abundant catalysts, which can be sustainably produced and implemented, is essential to many processes. In this work we present unsupported iron nanoparticles as an efficient catalyst for selective acetylene hydrogenation under industrially relevant front-end conditions. Additionally, the selectivity and the activity of this catalyst can be easily moderated by the addition of carbon monoxide. The iron nanoparticles were prepared in an environment completely free of water or air using condensed ammonia at −78 °C. State of the art X-ray diffraction and scanning electron microscopy were used to determine the crystal structure, morphology, and purity. The catalyst showed stable performance over several experiments and, other than an agglomeration of the unsupported and unstabilized particles, no changes to the catalyst were detected before and after the reactions.

Polyoxometalate‐Based Metal Organic Frameworks: Recent Advances and Challenges

“…[42] The technology of acetylene semi-hydrogenation to olefins is of great significance in the field of purification of ethylene. [43,44] Based on this, Liu et al [45] constructed separated single Pd atoms in POMOF to achieve highly selective acetylene semihydrogenation in an ethylene-containing gas stream (Figure 6). They synthesized Pd single-atom catalysts in situ and confined the Pd(acac)2 precursors between two-dimensional layers.…”

“…Ethylene, an important component of plastics production, is mainly produced commercially by the petroleum industry [42] . The technology of acetylene semi‐hydrogenation to olefins is of great significance in the field of purification of ethylene [43,44] . Based on this, Liu et al [45] .…”

[Pd(2-pymo)2]n/Al2O3 as MOF single site catalyst for the selective hydrogenation of acetylene

“…The as-synthesized [Pd(2-pymo)2]n powder was tested for its catalytic performance in the selective hydrogenation of acetylene under industrially relevant front-end conditions (Scheme 1 and Table 1). The applied reactor setup for fixed-bed catalyst testing under continuous gas feed conditions and online product analysis was recently reported by Hock et al [10][11] For the experiments a typical feed composition of an acetylene removal unit (ARU) according to Gislason et al [38] consisting of 39.00 mol% ethylene, 35.24 mol% methane, 25.00 mol% hydrogen, 0.40 mol% acetylene, 0.33 mol% propane (internal standard) and 250 ppm carbon monoxide was used (Table 1 #1). Scheme 1.…”

“…[4,8] However, due to the importance of the reaction, there has been a lot of research with focus on enhancing catalytic properties for palladium catalysts or even developing new catalysts. [2,4,11] Here metal-organic frameworks (MOFs) with their chemical versatility, high surface area and pore size variability, offer the possibility of directing selectivity and enhance the activity of the selective acetylene hydrogenation. [13][14][15] Recent studies on this reaction with specially designed MOFs for the separation of acetylene [16][17][18][19][20][21] and MOFs as catalysts, e.g.…”

Effective Inhibition of Ethane Generation on Fe5C2 Nanoparticles Doped with ppm Level of Pd for Selective Hydrogenation of Acetylene

“…Studies have proven that Pd carbide is a more favorable structure in selective hydrogenation of acetylene, and it even presents more fantastic performance than PdAg alloy. , Based on this, the non-noble metal carbides are particularly attractive and promising considering their similar construction if employed as active component or carrier. Fe is the most commonly found non-noble metal but scarcely used as the main catalytic active component in acetylene hydrogenation at atmospheric pressure because of its inherent poor ability to dissociate hydrogen. , Like metal Pd and other metals, forming metal carbides by incorporating carbon atoms would poison Fe and bring worse catalytic hydrogenation activity. − Thus, using Fe carbide as a carrier to deposit a small amount of highly active Pd for acetylene hydrogenation is a compromise and perspective strategy to investigate the performance of iron carbide in selective hydrogenation of acetylene. On the other hand, Pd is a kind of precious metal and reducing usage of expensive Pd metal can save cost to meet economic incentives to produce catalysts.…”