Inverse NiAl2O4on LaAlO3–Al2O3: Unique Catalytic Structure for Stable CO2Reforming of Methane

Abstract

Ni supported on LaAlO3–Al2O3 (NLA) perovskite oxide was synthesized for syngas production via DRM and compared with Ni supported on γ-Al2O3 (NA) and La2O3(NL). The formation of LaAlO3 perovskite oxide structure involves interaction with octahedral sites of the alumina support, resulting in the enforced Ni–Al interaction with the underlying tetrahedral Al3+ sites when Ni was impregnated. As a result, the inverse NiAl2O4 spinel structure was formed, and it positively affects the catalytic activity. Catalytic studies show that NLA exhibited the most stable catalytic performance with the lowest carbon deposition. Furthermore, XRD of spent NA catalyst showed phase transformation of support from γ-Al2O3 to α-Al2O3. Therefore, the enhanced stability of the NLA catalyst throughout the 30 h DRM reaction is attributed to the enhanced lattice stability imparted by the inverse spinel structure and LaAlO3 nanocrystallites on the alumina support, both of which aid in minimizing agglomeration of Ni particles.