Upgrading Aqueous Furfural To 2-Methyl Furan Over Cu⁰/Cu₂O·SiO₂ Sites Via A Copper Phyllosilicate Precursor Without Extraneous Gas

Furfural?FUL?is substantially produced by transformation of polymeric xylan fraction of hemicellulose with the presence of acids,and moreover the furfural derived 2-methyl furan?2-MF?is a useful bio-gasoline additive.Here,we report that 2-MF can be selectively formed from FAL with a 90%yield at 220oC within 2h over Cu⁰/Cu₂O·SiO₂ sites via a copper phyllosilicate precursor without extraneous gas.Methanol is used for in situ generating high-purity hydrogen?92%content?,and the almost CO free atmosphere avoids the poison on the metal sites.The structure-activity relationship shows the Cu⁰ or Cu₂O or physically mixed Cu⁰ and Cu₂O is inactive,but the hydrogen-reduced copper phyllosilicate sample comprising of abundant Cu⁰/Cu₂O·SiO₂ sites with interfaces demonstrate high activity in both reactions in methanol decomposition and FUL hydrodeoxygenation.The network on converting of FUL to 2-MF includes tandem steps of FUL hydrogenation and furfural alcohol hydrogenolysis to target 2-MF,accompanied with the side-reactions of hydrogenation of furan-rings and ring-opening of 2-MF.The kinetics modeling shows that the rational manipulation of reaction parameters of temperatures,times,and H₂ amounts is the key for attaining high yields of 2-MF.Eventually,the crude FUL solution with 10 wt%water can be selectivity hydrodeoxygenated to 2-MF?with a 87.9%yield?at the used catalytic conditions.