Tunable interfaces of Mg-Zr composite oxides boost acid-base synergy for efficient transfer hydrogenation of benzaldehyde

Mg-Zr composite oxides with tailored Mg-O-Zr interfacial structure weresynthesized. • Synergistic Mg-O-Zr interfacial structure integrates matched acid-basic sites • Isopropanol transfer hydrogenation achieved superior benzyl alcohol yield(89.6%). • Robust stability retained benzyl alcohol yield 82.0% after four reuse cycles. Non-noble metal composite oxide catalysts Mg x Zr 1-x O y featuring an acid–base bifunctional synergistic structure were synthesized via the co-precipitation-calcination method. Under a nitrogen atmosphere, with isopropanol serving as both the hydrogen donor and solvent, selective transfer hydrogenation of benzaldehyde to benzyl alcohol was achieved. The characterization revealed that the optimized Mg 0.7 Zr 0.3 O y catalyst possesses a highly crystalline Mg-Zr mixed-oxide structure with well-matched acidic Zr 4+ sites and surface basic sites of different strengths, including weakly basic hydroxyl species and moderate basic sites associated with interfacial oxygen species. The catalyst exhibits uniform distribution of surface sites and an appropriate pore structure, thereby providing excellent adsorption capacity and mass transfer efficiency. Under optimized conditions, the catalyst delivered nearly full benzaldehyde conversion up to 96.5% and an 89.6% yield of benzyl alcohol, together with a low apparent activation energy of 54.55 kJ·mol⁻¹. Notably, the catalyst retained a BnOH yield of 82.0% after four recycling cycles, indicating remarkable cycling stability. Compared with noble metal catalysts and monometallic oxide catalysts, the developed Mg 0.7 Zr 0.3 O y catalytic system delivers high activity, excellent selectivity, while offering the advantages of low cost and facile synthesis. This provides an efficient and stable non-noble metal catalytic solution for the selective transfer hydrogenation of benzaldehyde to benzyl alcohol and offers mechanistic insights and design principles for acid-base bifunctional composite oxides. Download: Download high-res image (232KB) Download: Download full-size image