Synthesis of NiMoO4 ceramics by proteic sol-gel method and investigation of their catalytic properties in hydrogen production

• Published in: Materials chemistry and physics 2021-04, Vol.262, p.124301, Article 124301
• Main Authors: da Silva, Maíra V., Fajardo, Humberto V., Rodrigues, Thenner S., e Silva, Felipe A., Bergamaschi, Vanderlei S., Dias, Anderson, Siqueira, Kisla P.F.
• Format: Article
• Language: English
• Subjects: Ammonia; Catalysts; Catalytic properties; Chemical synthesis; Colorimetry; Differential thermal analysis; Differential thermogravimetric analysis; Ethanol; Gelatin; Hydrogen production; Molybdates; Nickel compounds; Raman spectra; Reforming; Roasting; Selectivity; Sol-gel chemistry; Sol-gel processes
• ISSN: 0254-0584; 1879-3312
• DOI: 10.1016/j.matchemphys.2021.124301

A proteic sol-gel route was used in the production of NiMoO4 catalysts, which used edible gelatin as a precursor. The triple helix structure of a protein in contact with identical structures acquires an unfolded form, which favors the interaction of the reactive groups of the gelatin (NH3+ and COO−) with the metallic ions (MoO42− and Ni2+). The synthesized catalysts were thoroughly characterized using techniques such as X-ray diffraction, thermogravimetric and differential thermal analysis, Raman scattering, scanning and transmission electron microscopies, UV–Vis spectroscopy, and colorimetry. The results showed that it is possible to prepare the phase-pure α-NiMoO4 polymorph only at temperatures above 700 °C, while a mixture of the polymorphs α and β were obtained at lower temperatures. The synthesized materials calcined at 300, 500, and 700 °C have their catalytic potentials tested in the ethanol steam reforming reaction aiming the production of hydrogen and presented a good performance. The results indicated that among tested materials, the sample calcined at 700 °C exhibited the highest stability, activity, and best selectivity relative to the product of interest. Edible gelatin was used as a precursor in the synthesis of NiMoO4 catalysts for hydrogen production from ethanol steam reforming and exhibited good performance. The triple helix structure in contact with identical structures acquires an unfolded form, which favors the interaction of the gelatin with the metallic ions during synthesis. Thus, the reactive groups of the gelatin, i.e. NH3+ and COO− interacting with the molybdate (MoO42−) and nickel (Ni2+) ions, respectively, in order to form the “puff”. [Display omitted] •NiMoO4 catalysts were prepared by proteic sol-gel method.•Edible gelatin was used as precursor in the synthesis of the catalysts.•NiMoO4 were used for hydrogen production from ethanol steam reforming.•NiMoO4 showed good performance for hydrogen production.