Hydrogenation of Nitrophenol via Nickel-Based Catalytic Membranes with Engineered Surface Affinity

Selective hydrogenation of nitro groups to amino groups is a crucial reaction in industries, with the hydrogenation of p-nitrophenol (PNP) to p-aminophenol (PAP) being a key step in the production of fine chemicals and environmental pollution mitigation. Conventional catalysts often suffer from nanoparticle agglomeration and poor separation, limiting their efficiency. Here, we developed Ni-based catalytic membranes derived from metal–organic frameworks (MOFs) with –NH2 groups to enhance catalytic performance and stability. The Ni/CMs were prepared by growing Ni-based precursors in situ on ceramic membranes (CMs) via hydrothermal synthesis and pyrolysis. Among three different Ni/CMs, Ni/CM-ABDC, using 2-aminobenzene dicarboxylic acid (ABDC) as the ligand, exhibited the highest catalytic activity, achieving the PNP reduction rate of 14.3 h–1 and its complete conversion in 90 min and maintaining high stability over five reaction cycles. This was due to the uniform dispersion of Ni nanoparticles (Ni NPs), the mesoporous N-doped carbon matrix, and the highest Ni0/Ni2+ ratio. In contrast, Ni/CM-Urea and Ni/CM-BDC showed inferior performance. Mechanistic studies revealed that the N-doped carbon matrix enhanced selective adsorption of PNP and desorption of PAP, promoting the hydrogenation process. This work demonstrates the potential of MOF-derived Ni/CMs for efficient hydrogenation of nitro-groups.