Liquid-phase hydrogenation of benzaldehyde to benzyl alcohol over NiCoAl‑R catalysts: Synergistic metal–metal oxide interfaces for enhanced catalytic performance

Non-noble metal NiCoAl-R catalysts with tunable Ni/Co molar ratios were rationally designed and synthesized for the liquid-phase selective hydrogenation of benzaldehyde to benzyl alcohol. A series of Ni x Co 1-x Al-R (x = 0.3, 0.5, 0.7) catalysts were successfully prepared, featuring a metal–metal oxide synergistic structure constructed via a hydrothermal–calcination–reduction method. The characterization revealed that the optimized Ni 0.5 Co 0.5 Al-R catalyst possesses an ideal "metal–metal oxide synergistic interface": the highest content of Ni 0 ensures superior intrinsic hydrogenation rates, while the spinel phase Co 3 O 4 effectively transfers electrons and anchors the active Ni 0 sites to prevent structural degradation. The well-defined mesoporous channels significantly enhance mass transfer and product diffusion, contributing to near-complete conversion of benzaldehyde (99.4%), a benzyl alcohol yield of 94.3%, and a low apparent activation energy of 73.74 kJ·mol⁻¹ . Furthermore, the catalyst demonstrated excellent recycling stability, maintaining a benzyl alcohol yield of 87.8% after reusing for five cycle. Compared with noble-metal-based counterparts, the developed NiCoAl-R catalytic system integrates high activity, excellent selectivity, robust structural stability, and distinct cost advantages, presenting a promising non-noble-metal paradigm for the selective hydrogenation of benzaldehyde with strong potential for industrial application.