Molecular synergistic synthesis of AIPO-18 zeolite-stabilized Pt nanocatalysts with high dispersion for the hydrogenation of levulinic acid to γ-valerolactone

Pt nanocatalysts have received enthusiastic attention in the field of clean energy technologies due to their high catalytic activity and selectivity. The growth size and dispersion of Pt particles play significant effects on the reaction activity, especially in high temperature catalytic reactions where catalysts are prone to deactivation due to agglomeration and sintering of Pt particles. Herein, the Pt nanoparticles were effectively stabilized on AIPO-18 molecular sieve by a biomolecule-mediated green synthesis method. Based on the biocompatibility and electrostatic synergy of carboxymethyl chitosan (CMC), a high degree of Pt nanoclusters dispersion in AIPO-18 zeolites was achieved. The hydroconversion of levulinic acid (LA)was carried out at 160°C and 2 MPa hydrogen pressure, and the LA conversion of Pt/AIPO-18 (5CMC) reached 95.2% and the selectivity of γ-valerolactone (GVL) was 97.9% after 2 h. Pt/AIPO-18 (5CMC) exhibited satisfactory results that superior to the initial reactivity of Pt/AIPO-18 (0CMC) after five runs.