Selective Activation of C–OH, C–O–C, or C═C in Furfuryl Alcohol by Engineered Pt Sites Supported on Layered Double Oxides
Yanru Zhu, Wenfang Zhao, Jian Zhang, Zhe An, Xiaodan Ma, Zhijun Zhang, Yitao Jiang, Lirong Zheng, Xin Shu, Hongyan Song, Xu Xiang, Jing He
Abstract
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.