Hydrogenation of furfural to furfuryl alcohol over MOF-derived Fe/Cu@C and Fe3O4/Cu@C catalysts

Abstract

Using Cu-MOF loaded with Fe(NO₃)₃ as a precursor (Fe(NO₃)₃/Cu-MOF), Fe/Cu@C and Fe₃O₄/Cu@C catalysts were prepared via heating under a H₂ or N₂ atmosphere, respectively. When Fe(NO₃)₃/Cu-MOF was heated under either atmosphere, the Cu-MOF was pyrolyzed and carbonized into porous carbon-coated Cu⁰ nanoparticles. Various techniques were used to study the formation of active species and the physicochemical properties of the catalysts. The catalytic performance of the as-obtained catalysts was evaluated using furfural hydrogenation. The Cu²⁺ and Fe³⁺ in the Fe/Cu@C catalyst were reduced to Cu⁰ and Fe⁰, respectively, and Fe⁰ particles were loaded onto the surface of the porous carbon. Cu²⁺ and Fe³⁺ in the Fe₃O₄/Cu@C catalyst were reduced to Cu⁰ and Fe₃O₄, respectively, and the Fe₃O₄ particles were embedded onto the surface of porous carbon to form an embedded structure. The catalytic furfural hydrogenation activity of Fe₃O₄/Cu@C was higher than that of Fe/Cu@C. The catalytic furfural hydrogenation using Fe₃O₄/Cu@C occurred via direct catalytic hydrogenation (with molecular hydrogen as the hydrogen source) and catalytic transfer hydrogenation (with i-propanol as the hydrogen donor). The direct catalytic hydrogenation activity of Fe₃O₄/Cu@C was superior to its catalytic transfer hydrogenation activity.