Copper-Based Intermetallic Electride Catalyst for Chemoselective Hydrogenation Reactions

Abstract

The development of transition metal intermetallic compounds, in which active sites are incorporated in lattice frameworks, has great potential for modulating the local structure and the electronic properties of active sites, and enhancing the catalytic activity and stability. Here we report that a new copper-based intermetallic electride catalyst, LaCuSi, in which Cu sites activated by anionic electrons with low work function are atomically dispersed in the lattice framework and affords selective hydrogenation of nitroarenes with above 40-times higher turnover frequencies (TOFs up to 5084 h) than well-studied metal-loaded catalysts. Kinetic analysis utilizing isotope effect reveals that the cleavage of the H-H bond is the rate-determining step. Surprisingly, the high carrier density and low work function (LWF) properties of LaCuSi enable the activation of hydrogen molecules with extreme low activation energy (E = 14.8 kJ·mol). Furthermore, preferential adsorption of nitroarenes via a nitro group is achieved by high oxygen affinity of LaCuSi surface, resulting in high chemoselectivity. The present efficient catalyst can further trigger the hydrogenation of other oxygen-containing functional groups such as aldehydes and ketones with high activities. These findings demonstrate that the transition metals incorporated in the specific lattice site function as catalytically active centers and surpass the conventional metal-loaded catalysts in activity and stability.

Stable single platinum atoms trapped in sub-nanometer cavities in 12CaO·7Al2O3 for chemoselective hydrogenation of nitroarenes

“…Supplementary Fig. 35 shows bands at 1527 and 1349 cm −1 , associated with asymmetric stretching (ν as ) and symmetric stretching (ν s ) vibration frequencies of nitro groups, respectively 56,57 . Notably, the intensity of the 1349 cm −1 bands for CaO and Al 2 O 3 reduce gradually with the increased vacuum and cell temperature.…”

Simple Chemical Synthesis of Ternary Intermetallic RENi₂Si₂ (RE = Y, La) Nanoparticles in Molten LiCl–CaH₂ System

“…12 m 2 /g with a micro-level particle size. 15,16) Hence, the chemical synthesis method demonstrated in this study is highly advantageous in preparing metal silicide nanoparticles with high surface area in a simpler manner. Figure 3 shows SEM images of the prepared YNi 2 Si 2 and LaNi 2 Si 2 .…”

“…Nickel silicide is an attractive catalyst to show high performances in CO methanation, 1,2) hydrogenation, 39) hydrodesulfurization, 1012) photocatalytic decomposition of nitrogen monoxide 13) and electro-chemical hydrogen evolution. 14) In addition, rare earth metal doped intermetallic silicide catalysts have been reported to exhibit tremendous improvement in the catalytic activity of transition metals, such as LaCu 0.67 Si 1.33 , 15) LaCoSi, 16) LnRuSi (Ln = La Nd) 17,18) and LnNiSi, 19) due to the electron donation from the rare earth metals. The metal silicide catalysts are so fascinating that they are inexpensive and chemically stable.…”

Effect of Electronic Correlations on the Electronic Structure, Magnetic and Optical Properties of the Ternary RCuGe Compounds with R = Tb, Dy, Ho, Er

“…A number of interesting magnetic and electric properties of practical and fundamental importance were found in different compounds of the RTX series, including magnetocaloric effect (MCE) [ 5 ] of giant [ 6 , 7 , 8 , 9 , 10 ] and large [ 11 , 12 , 13 ] magnitude and magnetoresistance, an antiferromagnetic to ferromagnetic order transition [ 14 , 15 ] and rich magnetic transition phase diagram [ 16 , 17 , 18 ]. Very recently, another promising application of some RXT was revealed as intermetallic electrides [ 19 , 20 ]. Most of these properties are related to the coupling of the R-4f electronic states (localized) and other electronic states (itinerant) in the electronic system.…”