Syngas Production from Dry Reforming of Methane over Nano Ni Polyol Catalysts

Zhao

et al. 2020

Ind. Eng. Chem. Res.

A series of Ni−Zr catalysts with different Ni loadings were prepared by a novel one-step urea hydrolysis method and compared to the 10Ni/ZrO 2 catalyst prepared by the ethanol impregnation method. The catalysts were tested in dry reforming of methane (DRM) at 750 °C with a mixed flow of CH 4 /CO 2 /Ar = 10:10:80 and GHSV = 24,000 h −1 . The materials were characterized by means of N 2 adsorption−desorption, Xray diffraction, temperature-programmed reduction by H 2 , temperature-programmed desorption of CO 2 , X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis coupled with mass spectrometry. 10Ni−Zr and 15Ni−Zr catalysts prepared by the one-step method exhibited higher activity, long-run stability, and selectivity of H 2 /CO compared to 10Ni/ZrO 2 catalysts. This could be ascribed to the smaller Ni crystallite size, increased specific surface area, and enhanced weak-and medium-strength basic sites over reduced 10Ni−Zr and 15Ni−Zr catalysts. The 10Ni−Zr and 15Ni−Zr catalysts demonstrated the suppression of metallic nickel sintering because of the formation of NiO−ZrO 2 solid solution, leading to the stronger interaction between Ni and the ZrO 2 matrix. Moreover, stability enhancement for these catalysts was possibly linked to a higher amount of adsorbed oxygen species, as confirmed by XPS.

Section: Resultsmentioning

confidence: 99%

One-Step Synthesis of Highly Active and Stable Ni–ZrO_x for Dry Reforming of Methane

Zhao

et al. 2020

Ind. Eng. Chem. Res.

“…surface. These oxygen species then enable the oxidation (gasification) of intermediate carbonaceous species that originate from CH4 decomposition [62,63]. The gasification of intermediate carbonaceous species on the Ni/Zr catalyst is also enhanced by the existence of lattice defects (oxygen vacancies) offering enhanced O 2-lability, as evidenced by the TPR measurements presented in ref.…”

Section: Catalytic Stabilitymentioning

confidence: 92%

The Relationship between Reaction Temperature and Carbon Deposition on Nickel Catalysts Based on Al2O3, ZrO2 or SiO2 Supports during the Biogas Dry Reforming Reaction

et al. 2019

The tackling of carbon deposition during the dry reforming of biogas (BDR) necessitates research of the surface of spent catalysts in an effort to obtain a better understanding of the effect that different carbon allotropes have on the deactivation mechanism and correlation of their formation with catalytic properties. The work presented herein provides a comparative assessment of catalytic stability in relation to carbon deposition and metal particle sintering on un-promoted Ni/Al2O3, Ni/ZrO2 and Ni/SiO2 catalysts for different reaction temperatures. The spent catalysts were examined using thermogravimetric analysis (TGA), Raman spectroscopy, high angle annular dark field scanning transmission electron microscopy (STEM-HAADF) and X-ray photoelectron spectroscopy (XPS). The results show that the formation and nature of carbonaceous deposits on catalytic surfaces (and thus catalytic stability) depend on the interplay of a number of crucial parameters such as metal support interaction, acidity/basicity characteristics, O2– lability and active phase particle size. When a catalytic system possesses only some of these beneficial characteristics, then competition with adverse effects may overshadow any potential benefits.

Journal of Colloid and Interface Science

“…The supported nickel is commonly studied because of its low cost and better availability. However, the supported nickel catalyst has a major problem such as carbon deposition and leads to deactivation of the catalyst and/or a plugging of the tubes [8][9][10][11]. Because of that reason, it is impossible to avoid carbon formation under low or unity CO 2 /CH 4 ratios using nickel catalyst.…”

Section: Introductionmentioning

confidence: 99%

Catalytic performance of activated carbon supported cobalt catalyst for CO 2 reforming of CH 4

Zhang

et al. 2014

Syngas production by CO2 reforming of CH4 in a fixed bed reactor was investigated over a series of activated carbon (AC) supported Co catalysts as a function of Co loading (between 15 and 30wt.%) and calcination temperature (Tc=300, 400 or 500°C). The catalytic performance was assessed through CH4 and CO2 conversions and long-term stability. XRD and SEM were used to characterize the catalysts. It was found that the stability of Co/AC catalysts was strongly dependent on the Co loading and calcination temperature. For the loadings (25wt.% for Tc=300°C), stable activities have been achieved. The loading of excess Co (>wt.% 25) causes negative effects not only on the performance of the catalysts but also on the support surface properties. In addition, the experiment showed that ultrasound can enhance and promote dispersion of the active metal on the carrier, thus improving the catalytic performance of the catalyst. The catalyst activity can be long-term stably maintained, and no obvious deactivation has been observed in the first 2700min. After analyzing the characteristics, a reaction mechanism for CO2 reforming of CH4 over Co/AC catalyst was proposed.