Ni-Mediated Redox Engineering Enabled In Situ Construction of Oxygen Vacancies on MnO/C for Furfural Selective Hydrogenation in Ethanol

Abstract

The selective hydrogenation of biomass-derived furfural (FF) to high-value furfuryl alcohol (FA) is critical for the sustainable production of furan-based chemicals. However, designing a catalyst that can selectively hydrogenate C═O bonds is still a huge challenge. Herein, we proposed a Ni-mediated redox engineering strategy to synthesize carbon-supported MnO and Ni catalysts (MnxNiy/C) via one-pot pyrolysis of sodium alginate aerogel, leveraging the reduction potential difference between Ni2+/Ni and Mn2+/Mn to in situ construct oxygen vacancies (OVs) on MnO for selective C═O bond activation in FF. Systematic characterizations and comparative experiments confirmed that the introduction of Ni significantly promoted the in situ generation of OVs on MnO. By optimizing the Mn/Ni molar ratio, Mn1Ni1/C achieved the highest OV concentration, which substantially enhanced its adsorption strength toward the C═O bond in FF, reduced the apparent activation energy, and suppressed side reactions. Using ethanol as both solvent and hydrogen donor, Mn1Ni1/C delivers a 96% FA yield, markedly surpassing those of MnO/C (48%) and the physical mixture of MnO/C and Ni/C (58%). Moreover, Mn1Ni1/C exhibits excellent cycling stability and convenient magnetic separation for recovery. This in situ OV construction strategy provides new insights into the rational design of high-performance biomass hydrogenation catalysts, advancing the sustainable valorization of biomass resources.