Unraveling the Dependence of Critical Active Sites of WOx on Rh/WOx Catalysts in Tetrahydrofurfuryl Alcohol Hydrogenolysis

Taking the background of the ambiguous role of oxophilic metal oxide in metal-acid bifunctional catalysts for the important field of tetrahydrofurfuryl alcohol (THFA) hydrogenolysis, a linear relationship between the W═O/W–OH content in sub-nano-Rh-supported WOx and 1,5-pentanediol (1,5-PeD) yields from THFA hydrogenolysis has been established. It reveals that the higher reduction temperature promotes the surface Rh/W ratio. Thus, hydrogen spillover is facilitated, leading to more surface W═O structures and thereby more in-situ-reduced W–OH generation. W–OH structures work as the active sites to provide in situ Brønsted acid, resulting in enhanced selective activation for secondary C–O bonds of THFA. This discovery reveals the unique role of the surface structure on oxophilic metal oxide in chemoselective hydrogenolysis of the secondary C–O bond in polyols.