Selective Activation of C–OH, C–O–C, or C═C in Furfuryl Alcohol by Engineered Pt Sites Supported on Layered Double Oxides

The selective activation of targeted bonds in biomass-derived furfural or furfuryl alcohol with complex chemical linkages (C–C/C–H/C–O, C═C/C═O, or C–O–H/C–O–C) is of great challenge for biomass upgrading, expecting well-defined catalyst and definite catalytically active sites. This work demonstrates an efficient targeted activation to C–OH, C–O–C, or C═C by engineering the structure of catalytic Pt sites, affording 2-methylfuran (2-MF), tetrahydrofurfuryl alcohol (THFA), or 1,2-pentanediol (1,2-PeD) as product in the hydroconversion of furfuryl alcohol. The catalytic Pt sites have been engineered as atomic Pt, coordination unsaturated Pt–Pt in atom-thick dispersion, or coordination unsaturated 3D Pt–Pt by tailoring the Pt dispersion (single atom, 2D cluster, or 3D cluster) on Mg and Al-containing layered double oxide (Mg(Al)O) support. The selective activation of C–OH, C–O–C, or C═C has been traced with the FT-IR spectra recorded surface reaction. On atomic Pt, C–O–H is easily activated, with the assistance of Mg(Al)O support, with O-terminal adsorption without affecting furan C–O and C═C. However, C═C in the furan ring is easier to be activated on coordination-unsaturated Pt–Pt in atom-thick dispersion, resulting in a step-by-step hydrogenation to generate THFA. On coordination-unsaturated 3D Pt–Pt, the hydrogenolysis of furan ring is favored, resulting in the cleavage of furan C–O to produce 1,2-PeD. Also, the Mg(Al)O supports derived from Mg and Al layered double hydroxides (LDHs) here also play a key role in promoting the selectivity to 1,2-PeD by providing basic sites.