Synthesis of nanostructured fcc/hcp hollow Ni particles by ultrasonic spray pyrolysis and its dry reforming catalytic properties

• Published in: Powder technology Vol. 356; pp. 119 - 128
• Main Authors: Aghaali, Mohammad Hadi, Firoozi, Sadegh
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.11.2019; Elsevier BV
• Subjects: Aluminum oxide; Carbon dioxide; Catalytic activity; Chemical synthesis; Conversion; Crystallites; Crystals; Dry reforming; Ethanol; Hcp nickel; Methane; Morphology; Nickel; Particulates; Precursors; Pyrolysis; Reducing agents; Reforming; Spray pyrolysis; Sucrose; Sugar; Hcp nickel; Dry reforming; Spray pyrolysis; Morphology
• ISSN: 0032-5910; 1873-328X
• DOI: 10.1016/j.powtec.2019.08.023

Hollow nickel particles were synthesized via ultrasonic spray pyrolysis using ethanol or sucrose as the reducing agents, and nickel nitrate precursor solution in a temperature range of 500 to 800 °C. At 500–600 °C hcp Ni was the main synthesis product, and at 700–800 °C fcc Ni was formed. Ethanol effectively lowered the particle and crystallite sizes. The synthesized sample with ethanol at 700 °C had a specific surface area of 106 m2/g with a non-uniform meso/macroporous structure. The catalytic activity of the synthesized Ni particles for dry reforming of CH4 at 750 °C yielded 90% for the conversion of CH4. Al2O3 was also added to the precursor solution to provide active support for Ni particles. The synthesized Ni/Al2O3 particles yielded 89% and 70% conversion for CH4 and CO2, respectively, which shows the hollow structures of Ni combined with Al2O3 support is effective for the dry reforming of CH4. [Display omitted] •Ultrafine Ni macroporous hollow particles synthesized via ultrasonic spray pyrolysis.•Metastable hcp Ni at low and stable fcc Ni was formed at high synthesis temperatures.•Ni/Al2O3 achieved 89% and 70% CH4 and CO2 conversion in dry reforming of CH4 at 750 °C.•Reaction temperature and ethanol concentration controlled morphology of Ni particles.