Can formate dehydrogenase from Candida boidinii catalytically reduce carbon dioxide, bicarbonate, or carbonate to formate?

Carbon gasification from Fe–Ni catalysts after methane dry reforming

Ni/γ-Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> -550 and Ni/γ-Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> -800 catalysts (calcined at 550°C and 800°C in the catalyst preparation) were prepared with a impregnation method. Steam reforming of acetic acid as a model compound of bio-oil for hydrogen production had been investigated on the catalysts. The fresh catalysts were characterized by X-ray diffraction (XRD), temperature programmed reduction (TPR-H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) and specific surface area analysis (BET). The spent catalysts were characterized by temperature programmed oxidation (TPO), differential thermal analysis (DTA), X-ray photoelectron spectroscopy (XPS). The results showed that the Ni/γ-Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> -800 catalyst exhibited higher catalytic activity and lower coke formation than Ni/γ-Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> -550. This was due to the formation of nickel aluminate at higher calcination temperature in the catalyst preparation. Two types of carbon species: Ni <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> C and graphitic carbon, were deposited on the Ni/γ-Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> -550 catalyst and only one type of carbon species: graphitic carbon, was deposited on the Ni/γ-Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> -800 catalyst. Higher calcination temperature in the catalyst preparation promoted the conversion of Ni <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> C.

CeO2 nanooctahedrons, nanorods, and nanocubes were prepared by the hydrothermal method and were then used as supports of Cu-based catalysts for the water-gas shift (WGS) reaction. The chemical and physical properties of these catalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), N2 adsorption/desorption, UV-Vis spectroscopy, X-ray photoelectron spectroscopy (XPS), hydrogen temperature-programmed reduction (H2-TPR) and in situ diffuse reflectance infra-red fourier transform spectroscopy (DRIFTS) techniques. Characterization results indicate that the morphology of the CeO2 supports, originating from the selective exposure of different crystal planes, has a distinct impact on the dispersion of Cu and the catalytic properties. The nanooctahedron CeO2 catalyst (Cu-CeO2-O) showed the best dispersion of Cu, the largest amount of moderate copper oxide, and the strongest Cu-support interaction. Consequently, the Cu-CeO2-O catalyst exhibited the highest CO conversion at the temperature range of 150–250 °C when compared with the nanocube and nanorod Cu-CeO2 catalysts. The optimized Cu content of the Cu-CeO2-O catalysts is 10 wt % and the CO conversion reaches 91.3% at 300 °C. A distinctive profile assigned to the evolution of different types of carbonate species was observed in the 1000–1800 cm−1 region of the in situ DRIFTS spectra and a particular type of carbonate species was identified as a potential key reaction intermediate at low temperature.

Carbon dioxide reforming of methane to synthesis gas over Ni-MCM-41 catalysts

Methane dry reforming with CO 2: A study on surface carbon species

Effect of O2 and temperature on the catalytic performance of Ni/Al2O3 and Ni/MgAl2O4 for the dry reforming of methane (DRM)

We have studied the interaction of ethylene on Co(0001) in detail by X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS). At 130 K, the chemisorption and decomposition of C2H4 were found to depend on the vacant sites available on Co(0001). C2H4 chemisorbs dissociatively at low exposures but both dissociatively and molecularly at large exposures. Upon heating, some C2H4(a) desorbs molecularly from the surface, releasing vacant surface sites that result in the simultaneous decomposition of other C2H4(a). C2H2(a) is the surface intermediate for the decomposition of C2H4(a) on Co(0001). At elevated temperatures, C2H2(a) simultaneously undergoes the direct dehydrogenation and the cyclopolymerization–dehydrogenation to form surface C2 cluster and graphitic carbon on Co(0001). At 500 K, C2H4 directly decomposes on Co(0001), forming surface atomic carbon. These results provide novel information on the chemisorption and decomposition of C2H4 on Co(0001) and the nature of resulted carbon species, greatly deepening our fundamental understanding of the relevant heterogeneous catalytic reactions catalyzed by Co-based catalysts and the growth of graphene on Co surfaces by chemical vapor deposition.

In this paper, we have demonstrated a simple surfactant-free solution method for the synthesis of sea urchin-like nickel carbonate hydroxide, which was characterized by field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, thermal gravimetric analysis, nitrogen adsorption–desorption isotherms, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). Two types of carbonate species, a surface unidentate carbonate-like species and a crystal lattice carbonate species, were proposed based on the FTIR and symmetry analysis. The toxic ion-exchange properties towards As(V), Cd(II), and Cu(II) ions were investigated. At pH 5.0, the exchange capacities of Cd(II) and Cu(II) ions were 120.5 and 109.3 mg g−1, respectively, through the ion-exchange between nickel ions with them, which was confirmed by XPS. For As(V) ion removal, the maximum exchange capacity was 49.6 mg g−1 without any pH adjustment, which should be of importance for water treatment. Furthermore, a novel ion-exchange mechanism between the surface unidentate carbonate-like species and As(V) ions was proposed, which was revealed by XPS and FTIR.

Characterization and Analysis of Carbon Deposited during the Dry Reforming of Methane over Ni/La2O3/Al2O3 Catalysts

An isotopic tracer study of the deactivation of Ru/Ti0 2 catalysts during Fischer-Tropsch synthesis

Hydrogen production from glycerol dry reforming over Ag-promoted Ni/Al2O3

A variable temperature infrared spectroscopy study of CaA zeolite dehydration and carbonate formation.

The interaction of carbon dioxide with metallic Nd overlayers and pre-oxidised Nd films on Cu(100) has been investigated by XPS, UPS, Δϕ measurements and temperature-programmed desorption (TPD). Corresponding observations have also been made with H2O in place of CO2. Exposure of Nd overlayers to CO2 at 300 K leads initially to complete dissociation of the molecule with formation of an oxygen-deficient neodymium oxide. Further gas exposure leads to the formation of a CO(–)x(x= 2 or 3) species, which on raising the temperature decomposes, yielding first CO and then CO2 in the gas phase. The interaction of CO2 with pre-oxidised Nd films proceeds in a manner which is essentially independent of the nature of the pre-oxidising agent (O2 or CO2 itself). Quantitative evaluation of the XP spectra indicates that oxide to carbonate conversion occurs leading to the formation of one or more types of carbonate species. The relevance of the work to the poisoning characteristics of Cu/lanthanide alloy-derived methanol synthesis catalysts is noted.

Renewable hydrogen from glycerol reforming over nickel aluminate-based catalysts

Solid-state 13C nuclear magnetic resonance (NMR) spectroscopy was used in this work to analyze the physical and chemical properties of plasma blacks and carbon deposits produced by thermal cracking of natural gas using different types of plasma reactors. In a typical configuration with a double-chamber reactor, N2 or Ar was injected as plasma working gas in the first chamber and natural gas was injected in the second chamber, inside the arc column. The solid residue was collected at different points throughout the plasma apparatus and analyzed by 13C solid-state NMR spectroscopy, using either cross polarization (CP) or direct polarization (DP), combined with magic angle spinning (MAS). The 13C CP/MAS NMR spectra of a number of plasma blacks produced in the N2 plasma reactor showed two resonance bands, broadly identified as associated with aromatic and aliphatic groups, with indication of the presence of oxygen- and nitrogen-containing groups in the aliphatic region of the spectrum. In contrast to DP experiments, only a small fraction of 13C nuclei in the plasma blacks are effectively cross-polarized from nearby 1H nuclei and are thus observed in spectra recorded with CP. 13C NMR spectra are thus useful to distinguish between different types of carbon species in plasma blacks and allow a selective study of groups spatially close to hydrogen in the material.