One-pot synthesis of aluminum oxyhydroxide matrix-entrapped Pt nanoparticles as an excellent catalyst for the hydrogenation of nitrobenzene

Abstract

Aluminum oxyhydroxide matrix-entrapped Pt nanoparticles (Pt/AlO(OH)) were synthesized via a one-pot procedure, by the reduction of Pt⁴⁺ followed by the hydrolysis of Al(O-sec-Bu)₃. Small and well-dispersed Pt nanoparticles were entrapped into an aluminum oxyhydroxide matrix and confirmed by TEM characterization. FTIR analysis indicated that the Pt/AlO(OH) catalyst had a large amount of surface hydroxyl groups, which potentially improves its dispersibilty in aqueous solution. The as-prepared catalyst was used for the hydrogenation of nitrobenzene to aniline at 30 °C and atmospheric hydrogen pressure. Compared with other alcohol–water media, the hydrogenation reaction in a methanol–water medium exhibited a maximum turnover frequency (TOF) of 3620 h⁻¹. A complete conversion of nitrobenzene with a selectivity of 99.0% was obtained with an increase of time to 150 min.