Recent progress in Ni and Al-containing layered double hydroxides for dry reforming of methane

Layered double hydroxides (LDHs)-based catalysts containing NiAl have been widely used and investigated for years due to their high conversion efficiency, high basicity, and low coke formation as an alternative to noble metals in the dry reforming of methane (DRM) processes. Due to the synergetic effect between Ni and Al, there is a significant potential for the development of these catalysts. Hence, the impact of NiAl-LDH-based LDHs and the related parameters are reviewed on DRM processes. Different metals have been incorporated into the NiAl-LDH structure to enhance its effectiveness and to extend its durability for prolonged use. Various studies have claimed that the increase in the Ni/M ratio positively affects the DRM and Mg, Ce, La and Y are the frequently used metals to provide the catalytic effect, especially on the NiAl-LDH. Despite the constructive achieved developments, further enhancements are still required to address issues such as the decline in activity and limited lifespan of these catalysts. In this review, comprehensive information is given on the preparation techniques of LDHs and effects of preparation techniques on the characteristics and structural properties of NiAl-LDHs. In addition, the use of NiAl-LDHs in DRM processes and metal additives that will create a synergistic effect to increase catalytic performance and extend lifespan are discussed. Furthermore, the influences of operating conditions on catalytic performance, activity losses, and reaction mechanisms are reviewed. Finally, current developments and possible improvements are discussed.