Hydrogenation of CO2 into formic acid using a palladium catalyst on chitin

Abstract

Recently, the conversion from a C-1 source of carbon dioxide into chemicals has drawn wide attention. An efficient synthesis process for formic acid (FA) via the hydrogenation of CO₂ was established with a palladium catalyst on chitin under mild conditions in this study. The heterogeneous catalyst was prepared via a simple wet-impregnation method and then characterized by FT-IR, ICP, XRD, FESEM, TEM and XPS. Under optimal conditions, 0.25%Pd/chitin exhibited high catalytic activity with a turnover frequency of 257 h⁻¹, under 4 MPa (P_CO2 = P_H2 = 2 MPa) in water at 60 °C after 1 h. The results indicated that acetamide groups in chitin promoted the distribution of Pd particles on the surface and accelerate the hydrogenation of carbon dioxide due to its coordinating ability to transition metals and Lewis basic properties. This study highlights the beneficial role of chitin as a support for heterogeneous catalysts and provides a clue for future development of catalysts for CO₂ hydrogenation.