Effect of Solvothermal Treatment on Physical Properties of Nickel and Aluminum Based Oxide Powders Synthesized by Coprecipitation

Abstract

Improvements of the catalytic efficiency of nickel–aluminum oxides in reforming reactions for hydrogen production have been achieved by the development of synthesis processes that provide powders with high surface area. The reduction of the crystallization temperature is one of the procedures in this direction. In this work, the effect of solvothermal treatment on coprecipitated gels with 15 wt% nickel content in alumina matrix was evaluated. Powders were obtained by coprecipitation with and without treatment of gels under n-butanol vapor pressure at 150oC. Products were characterized by TG/DTA, X-ray diffraction, specific surface area measurements, scanning electron microscopy and laser beam scattering for granulometric distribution determination. The results showed that calcined powders have high specific surface area (ranging from 170 to 260 m2.g-1) and are composed by gamma alumina and nickel aluminate phases. Aging treatment did not promote hydroxides decomposition under solvothermal conditions, indicating the need of calcination step.

Dry reforming of methane: Effect of different calcination temperatures of Al2O3 and Mg‐Al2O3 supports on Ni catalysts

“…The electronic deficiency enables chemical reactions in these centres, thus making transition aluminas more active regarding the catalytic activity. [ 12 ]…”

“…The electronic deficiency enables chemical reactions in these centres, thus making transition aluminas more active regarding the catalytic activity. [12] According to the literature, another possible strategy to modify the acidity-basicity properties of the catalyst surface and prevent carbon deposition is using alkali promoters, such as alkaline metal oxides and noble metal oxides. [13] Some promoters, such as Ag, can change the type of coke formed on the metal surface from encapsulated carbon filaments to amorphous carbonaceous species.…”