Modulating morphology and textural properties of ZrO2 for supported Ni catalysts toward dry reforming of methane

This work presents a facile and efficient approach to modulate morphology and textural properties of ZrO2 through ammonium fluoride-urea assisted hydrothermal (FUAH) method with diverse parameters including molar ratio of NH4F to zirconium (n(f/z)), molar ratio of urea to zirconium (n(u/z)), hydrothermal temperature (T-hydroth), and hydrothermal time (t(hydroth)), which serve as support for supported Ni catalysts toward dry reforming of methane (DRM) to produce synthesis gas. The plausible mechanism for forming ZrO2 supports with different morphologies under diverse hydrothermal conditions was proposed. Various characterization techniques were employed to investigate the effect of preparation parameters on the morphology and textural properties of the as-synthesized ZrO2 supports, as well as to reveal the structure-performance relationship of the Ni/ZrO2 catalysts prepared by L-arginine assisted incipient wetness impregnation method toward DRM reaction. The developed supported Ni catalyst on hierarchically structured ZrO2 with pinecone shape prepared by FUAH method (Ni/ZrO2-FUAH) demonstrates higher activity and stability for DRM than that on ZrO2 prepared by traditional hydrothermal method (Ni/ZrO2-H). The higher activity of Ni/ZrO2-FUAH than Ni/ZrO2-H can be ascribed to the higher Ni dispersion, smaller Ni crystalline size, and enhanced reducibility of NiO, significantly affected by morphology of support, as well as the higher coke-resistance catalytic stability can be ascribed to smaller Ni particle size and stronger Ni-support interaction, strongly dependent on morphology and textural properties of ZrO2 supports that affected by FUAH process parameters. The outstanding catalytic performance of the developed Ni/ZrO2-FUAH catalyst allows it to be a promising candidate for synthesis gas production through DRM reaction. (c) 2017 American Institute of Chemical Engineers AIChE J, 63: 2900-2915, 2017