Regulating Si/Al Role of MCM-41 with Graphite Carbon-Coated Co NPs for Efficient Hydrogenation of Furfural to Furfuryl Alcohol

The catalytic hydrogenation of furfural (FF) to furfuryl alcohol (FOL) using metal-loaded mesoporous molecular sieves represents a significant research area. In this work, a mesoporous molecular sieve with graphite carbon-coated Co NPs (Co@CN/Al-MCM-41) was successfully synthesized by vacuum-injecting the precursor solution into the MCM-41 molecular sieve and subsequent calcination. Using Co@CN/Al_0.1-MCM-41 as the catalyst, the selective hydrogenation of FF to FOL achieved a conversion rate of 91.2% under mild conditions at 120 °C, which is 2.85 times higher than that of Al-free Co@CN/MCM-41, with an FOL selectivity of 97.2%. The experimental results revealed a strong correlation between FF conversion and the Si/Al ratio of MCM-41 molecular sieve. Increasing the Al species content facilitated the formation of more Co NPs active sites because of the strong electrostatic interaction, thereby promoting the activation of FF and hydrogen and enhancing the catalytic activity of Co@CN/Al_0.1-MCM-41. Additionally, Co@CN/Al_0.1-MCM-41also exhibited stable performance over five consecutive cycles, which was attributed to the formation of graphite carbon-coated Co NPs structure during the synthesis process. This simple fabrication strategy provides a novel approach for the modification of mesoporous molecular sieves with excellent catalytic activities.