A Comparative Study of Hydrothermally Leached AlTM and AlTM-Rh (TM=Zr, V, Ce) Intermetallic Compounds for Catalytic Oxidation of Carbon Monoxide.

Rise of the mute assassin "carbon monoxide (CO)" levels impact all aerobic life. The elevated rates of CO concentration endure climatic and geographical characteristics that exacerbate air pollution. Herein, a simple approach for hydrothermal leaching (HyTL) of AlTM-Rh (Target material (TM)=Zr, V, Ce) and AlTM (TM=Zr, V, Ce) intermetallic compounds produces leached products of ZrO, VO, and CeO with Rhodium (Rh) as an active component.

Co FeGe Heusler Alloy Nanoparticle Catalysts for Propyne Hydrogenation and Ammonia Decomposition.

Heusler alloys (X YZ) can be a candidate for new catalysts as well as other intermetallic compounds. We previously found good catalytic properties of Co FeGe for selective hydrogenation of alkynes and developed nanoparticles of Co FeGe supported on SiO . However, the average diameter of the nanoparticles was 23 nm, which is not small enough compared to those of state-of-the-art nanoparticle catalysts.

Synthesis of Polynorbornadiene within the Pores of Activated Carbons: Effects on EDLC and Hydrogen Adsorption Performances.

Norbornadiene (NBD) is adsorbed on activated carbon (AC), and the adsorbed NBD is polymerized within the pores of AC. Two kinds of ACs─AC-2 with only micropores of ∼2 nm and AC-4 with not only micropores but also mesopores below 4 nm─are examined to study the effects of the hybridized polynorbornadiene (PNBD) on the electric double-layer capacitor and hydrogen adsorption performance. Various measurements are performed to determine the form of the hybridized PNBD inside the pores of AC.

Synthesis of CoFeGe Heusler alloy nanoparticles and catalysis for selective hydrogenation of propyne.

Although intermetallic compounds are attracting attention of catalysis researchers, ternary intermetallic catalysts have scarcely been investigated due the difficulty of synthesizing supported nanoparticles. In this study, we successfully synthesized SiO supported CoFeGe Heuslar alloy nanoparticles. This catalyst exhibited high catalytic performance for selective hydrogenation of propyne by nano-sizing.

High catalytic performance of Al-Pd-(Ru, Fe) icosahedral approximants for acetylene semi-hydrogenation.

Three cubic crystalline icosahedral approximants (C phase: AlPdFe, P phase: AlPdRu, P phase: AlPdRu) exhibit high ethylene selectivity of over 90% for hydrogenating acetylene at 150 °C. Moreover, the powdered P also demonstrates a high catalytic performance under an industry-like ethylene feed containing 0.5% acetylene as an impurity.

AuSi and AuSi: Electronically Equivalent but Different Polarity Superatoms.

A series of AuSi cluster anions ( = 1-4) were generated most abundantly by laser ablation of a AuSi alloy target. Photoelectron spectroscopy and density functional theory (DFT) calculation of AuSi ( = 1-4) revealed that AuSi can be viewed as an electronically closed superatom and is composed of a Si unit whose three adjacent edges of a single facet are bridged by three Au atoms. Such phase-segregated structure is facilitated by aurophilic interaction between the three Au atoms and results in a large permanent dipole moment (4.

Catalytic Properties of Heusler Alloys for Steam Reforming of Methanol.

Intermetallic compounds have attracted research attention in catalysis because of their unique catalytic properties. Recently, a group of intermetallic compounds, referred to as Heusler alloys (XYZ), has been investigated as new catalysts. In this study, catalytic properties of 14 Heusler alloys with X = Fe, Co, Ni, or Cu; Y = Ti, Mn, or Fe; Z = Al, Si, Ga, Ge, or Sn for the steam reforming of methanol were examined.

Enhanced catalytic activity of inhomogeneous Rh-based solid-solution alloy nanoparticles.

Catalytic Rh-based alloy nanoparticles (NPs) with inhomogeneous solid-solution structures were prepared from homogeneous solid-solution alloy NPs. Compared with homogeneous alloy NPs, these inhomogeneous alloy NPs exhibited enhanced catalytic activity and superior catalytic durability. Homogeneous solid-solution alloy NPs consisting of Rh and other immiscible noble metals were synthesized by laser-induced nucleation method in metallic ion solutions.

Correction to "Heusler Alloys: A Group of Novel Catalysts".

[This corrects the article DOI: 10.1021/acsomega.6b00299.

Ability of hydrogen storage CeNi Ga and MgNi alloys to hydrogenate acetylene.

Hydrogen storage properties and reactivity for hydrogenation of acetylene in a series of CeNi Ga ( = 0, 0.5, 0.75, 1, 1.

Catalysis-tunable Heusler alloys in selective hydrogenation of alkynes: A new potential for old materials.

Heusler alloys ( ) are well-established intermetallic compound materials in various fields because their function can be precisely adjusted by elemental substitution (e.g., ' ).

Probing Single Pt Atoms in Complex Intermetallic AlFe.

The atomic structure of a 0.2 atom % Pt-doped complex metallic alloy, monoclinic AlFe, was investigated using a single crystal prepared by the Czochralski method. High-angle annular dark-field scanning transmission electron microscopy showed that the Pt atoms were dispersed as single atoms and substituted at Fe sites in AlFe.

Understanding the catalytic activity of nanoporous gold: Role of twinning in fcc lattice.

Nanoporous gold (NPG) prepared by de-alloying AlAu exhibits correlation between the high catalytic reactivity towards CO oxidation and the density of twinning defects in the fcc lattice of NPG. It was also discovered that on the internal surface of NPG, quite common twinning defects can create close-packed rows of six-coordinated catalytically active Au atoms denoted as W-chains. In this work, using density functional theory methods, we investigate energy conditions for formation, thermal stability, and chemical reactivity of these active sites.

Heusler Alloys: A Group of Novel Catalysts.

In this study, we investigated the catalytic properties of various Heusler alloys for the hydrogenation of propyne and the oxidation of carbon monoxide. For propyne hydrogenation, CoFeGe alloy showed a higher activity than that of elemental Co, where neither Fe nor Ge showed any activity. This clearly indicates an alloying effect.

Twinning in fcc lattice creates low-coordinated catalytically active sites in porous gold.

We describe a new mechanism for creation of catalytically active sites in porous gold. Samples of porous gold prepared by de-alloying Al2Au exhibit a clear correlation between the catalytic reactivity towards CO oxidation and structural defects in the fcc lattice of Au. We have found that on the stepped {211} surfaces quite common twin boundary defects in the bulk structure of porous gold can form long close-packed rows of atoms with the coordination number CN = 6.

Insights into the dominant factors of porous gold for CO oxidation.

Three different porous Au catalysts that exhibit high catalytic activity for CO oxidation were prepared by the leaching of Al from an intermetallic compound, Al2Au, with 10 wt. %-NaOH, HNO3, or HCl aqueous solutions. The catalysts were investigated using Brunauer-Emmett-Teller measurements, synchrotron X-ray powder diffraction, hard X-ray photoelectron spectroscopy, field emission scanning electron microscopy, and transmission electron microscopy (TEM).

Optical properties of Group X-XII intermetallic compounds studied by HR-EELS.

Electronic structure of d orbital states in transition metals is a key factor for their physical properties and chemical functions. Copper and intermetallic compound PdZn have good catalysis function for the methanol steam reforming reaction. Tsai et al.

Activation of Al-Cu-Fe quasicrystalline surface: fabrication of a fine nanocomposite layer with high catalytic performance.

A fine layered nanocomposite with a total thickness of about 200 nm was formed on the surface of an AlCuFe quasicrystal (QC). The nanocomposite was found to exhibit high catalytic performance for steam reforming of methanol. The nanocomposite was formed by a self-assembly process, by leaching the Al-Cu-Fe QC using a 5 wt% NaCO aqueous solution followed by calcination in air at 873 K.

Effect of electronic structures on catalytic properties of CuNi alloy and Pd in MeOH-related reactions.

We investigated the catalytic properties of a CuNi solid solution and Pd for methanol-related reactions and associated valence electronic structures. Calculations and X-ray photoelectron spectroscopy measurements revealed that the CuNi alloy has a similar valence electronic structure to Pd and hence they exhibited similar CO selectivities in steam reforming of methanol and decomposition of methanol. Samples prepared by various processes were found to have similar CO selectivities.