Synthesis of Ni‐Al layered double hydroxide via coprecipitation: Formation mechanism, synthesis intensification, and catalytic application

Abstract Herein, the formation mechanism of Ni‐Al layered double hydroxide (NiAl‐LDH) synthesized by coprecipitation was explored. Moreover, NiAl‐LDH was prepared in a rotating packed bed (RPB) under different rotation speeds, which shows that increasing the rotation speed decreases the lateral size and thickness of NiAl‐LDH, since high rotation speed accelerates the nucleation of NiAl‐LDH. Additionally, the Ni/mixed metal oxides (MMO) catalysts derived from NiAl‐LDH were prepared for maleic anhydride (MA) hydrogenation. Result shows that Ni/MMO catalyst obtained from NiAl‐LDH prepared under a higher rotation speed exhibits higher MA conversion due to its larger surface area and smaller nickel particle size. The Ni/MMO catalyst obtained from NiAl‐LDH prepared under 500 rpm exhibits 100% MA conversion and 100% succinic anhydride selectivity under 30°C and 2 MPa within 1 h. This work provides fundamental insight to understand the formation of NiAl‐LDH. Moreover, RPB as an effective technique to synthesize NiAl‐LDH and Ni‐based catalysts was validated.