American Chemical Society
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One-Step Synthesis of Highly Active and Stable Ni–ZrOx for Dry Reforming of Methane

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journal contribution
posted on 2020-06-12, 17:33 authored by Ye Wang, Qing Zhao, Yannan Wang, Changwei Hu, Patrick Da Costa
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/ZrO2 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 CH4/CO2/Ar = 10:10:80 and GHSV = 24,000 h–1. The materials were characterized by means of N2 adsorption–desorption, X-ray diffraction, temperature-programmed reduction by H2, temperature-programmed desorption of CO2, 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 H2/CO compared to 10Ni/ZrO2 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–ZrO2 solid solution, leading to the stronger interaction between Ni and the ZrO2 matrix. Moreover, stability enhancement for these catalysts was possibly linked to a higher amount of adsorbed oxygen species, as confirmed by XPS.