Steam reforming of tar from pyrolysis of biomass over Ni/Mg/Al catalysts prepared from hydrotalcite-like precursors

The Ni/Mg/Al catalysts were prepared from the calcination and reduction of hydrotalcite-like compounds containing Ni, Mg and Al, and applied to the steam reforming of tar from pyrolysis of biomass. The dependence of the composition and reduction pretreatment conditions on the catalytic performance was investigated. It is found that the Ni/Mg/Al catalyst with optimized composition of Ni/Mg/Al = 9/66/25 exhibited much higher activity, resistance to coke deposition, and stability than Al2O3- and MgO-supported Ni catalysts. The catalyst characterization using XRD, TPR, N2 and H2 adsorption, and TEM indicates that the Ni/Mg/Al catalyst after the reduction has a nanocomposite structure of Ni metal particles (about 8.5 nm) and Mg(Ni, Al)O particles (about 11.5 nm). Even after the catalytic use, the nanocomposite structure was maintained. High performance of the Ni/Mg/Al catalyst including the suppression of the aggregation of the metal particles can be caused by the nanocomposite structure.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideResearch highlights▶ Calcination–reduction of the hydrotalcite precursors gives Ni/Mg/Al catalysts. ▶ The optimized Ni/Mg/Al showed high activity and stability in tar steam reforming. ▶ The Ni/Mg/Al catalyst has a nanocomposite consisted of Ni particles and Mg(Ni, Al)O. ▶ The aggregation of Ni particles and coke deposition were suppressed on this catalyst.