Hydrogenation of levulinic acid to γ-valerolactone over single-atom Pt confined in Sn-modified MIL-101(Fe)

Abstract

We synthesize a Sn-modified MIL-101(Fe), which can confine Pt to the single-atom scale. This novel Pt@MIL(FeSn) catalyst efficiently hydrogenates levulinic acid to γ-valerolactone (TOF: 1386 h⁻¹, yield: >99%) at only 100 °C and 1 MPa of H₂via α-angelica lactone as an intermediate. This could be the first report on switching the reaction path from 4-hydroxypentanoic acid to α-angelica lactone under very mild conditions. Incorporating Sn into MIL-101(Fe) enables the creation of abundant micro-pores less than 1 nm and Lewis acidic sites that stabilize Pt⁰ atoms. The ensemble of active Pt atoms and a Lewis acid can synergistically enhance adsorption of the CO bond and facilitate dehydrative cyclization of levulinic acid.