A new approach to catalytic reactivity to study the influence of Mg in Ni-based Takovite-type catalysts via dry methane reforming

Abstract

Takovite and Mg@Takovite, with partial substitution of Ni by Mg, are Ni-based catalysts derived from hydrotalcite (layered double hydroxide) structures. They were synthesized by the solid crystallization phase method under alkaline conditions (pH = 9), calcined at 450 °C for 6 h to form oxide phases, and reduced under hydrogen at 650 °C for 1 h to produce the active Ni⁰ phase for catalytic dry reforming of methane (DRM). Structural and textural properties at different stages (fresh, calcined, reduced, tested) were analyzed using XRD, FTIR, BET, AAS, SEM, TEM, TPR-H₂, and TGA/DTA. Catalytic performance was evaluated in DRM at atmospheric pressure through two temperature cycles: cycle 1 (500–700 °C) and cycle 2 (700–500 °C). The study aimed (i) to investigate oxide phases obtained from hydrotalcites at low calcination temperatures compared with conventional oxides, and (ii) to assess catalytic activity, stability, and resistance to carbon deposition, particularly in cycle 2 at 500 °C, an industrially relevant low temperature for economic and energy efficiency. Mg@Takovite-c exhibited high activity and stability, maintaining performance at 500 °C without deactivation over 24 h. Mg addition enhanced surface area, promoted high Ni⁰ dispersion, tuned acid–base properties, improved reducibility, and suppressed carbon deposition, resulting in ~ 94% conversion and H₂/CO ≈ 0.92.

Graphical abstract