Ni Promotion by Fe: What Benefits for Catalytic Hydrogenation?

Abstract

Metallic nickel is known to efficiently catalyze hydrogenation reactions, but one of its major drawbacks lies in its lack of selectivity, linked to side-reactions of hydrogenolysis and over-hydrogenation. More selective hydrogenations can be obtained upon the introduction of a second metal in combination with Ni. Fe is an interesting choice, as it is a cheap and abundant metal. This review aims at discussing the advantages and constraints brought by the preparation procedures of bimetallic supported Ni–Fe nanoparticles, and at analyzing the benefits one can draw by substituting Ni–Fe supported catalysts for Ni monometallic systems for the catalytic hydrogenation of organic molecules. Specific formulations, such as Ni75Fe25, will be singled out for their high activity or selectivity, and the various hypotheses behind the roles played by Fe will be summarized.

Promotional Effect of Cu, Fe and Pt on the Performance of Ni/Al2O3 in the Deoxygenation of Used Cooking Oil to Fuel-Like Hydrocarbons

“…Regarding the oxidation state of the promoter metals after reduction, while the entirety of Cu is present in the metallic form, only~9% of iron is present as Fe 0 , the remainder being present as Fe 2+ or Fe 3+ . Since it has been reported that Fe 2 O 3 undergoes reduction to Fe 3 O 4 in the~300-400 • C range, while Fe 3 O 4 is reduced between~400 and 500 • C [34], it is unsurprising that after reduction at 400 • C most of the Fe detected by means of XPS is oxidic.…”

One-pot mechanochemical ball milling synthesis of the MnOx nanostructures as efficient catalysts for CO2 hydrogenation reactions

“…6 In recent years, the most studied CO 2 hydrogenation catalysts are nickel-based (Ni/ZrO 2 , Ni-Ga, and Ni/CeO 2 ); [7][8][9][10] typically, they have several shortcomings, such as their pyrophoricity, low stability, and fast deactivation. 11 Manganese-based materials, on the other hand, are not widely researched; however, they can be costeffective alternatives for catalyzing the CO 2 hydrogenation process. 12,13 The fifth most abundant metal in the earth's crust is manganese and it occurs with various types of mineral forms in nature.…”

Reduced graphene oxide decorated with Ni-Fe-Mo permalloy obtained by sputtering

“…The first difference is the increase of the bands due to sp 3 carbon atoms, more specifically it can be observed at 2918 and 2849 cm − 1 the C -H asymmetric and symmetric stretching, respectively, of methylene groups [38]. The increase of the CH 2 bands would suggest a partial reduction of some aromatic rings of graphene by the catalytic effect of NiFe metals [39]. Finally, another outstanding difference between the spectra of rGO and permalloy/rGO is the clear appearance of two peaks at 621 and 468 cm − 1 .…”