Hydrogenolysis of xylitol can produce value-added glycols and alcohols for industrial chemicals. However, it is often carried out under elevated temperature and pressure, causing unfavorable catalyst deactivation and significant formation of side products. Catalytic transfer hydrogenolysis of xylitol, under much milder conditions, is largely unexplored in this field. Herein, we reported transfer hydrogenolysis of xylitol with in situ-formed H-2 in batch slurry reactors over synergistic Pd-Pt/TiO2 catalysts. Although monometallic Pd/TiO2 and Pt/TiO2 catalysts display poor activity and selectivity, bimetallic Pd-Pt/TiO2 catalysts showed synergetic performances for tandem H-2 generation and hydrogenolysis of xylitol. A combined yield of 41.1% to propylene glycol and ethylene glycol was thus obtained on the Pd-Pt/TiO2 catalyst at 220 degrees C and 1 MPa N-2. Detailed structure-dependency studies on PdPt particle size (2.4-5.2 nm) revealed that C-H, C-O, and C-C bond cleavage displays strong size-determining trends. Therefore, conversion of xylitol displays an optimal selectivity toward glycols and alcohols with a PdPt particle size of approximately 4.4 nm. In addition, influence of experimental parameters, including temperature (200-230 degrees C), N-2 pressure (0-3 MPa), and alkali/xylitol molar ratio (0-0.25), was also studied with respect to conversion and production distribution. The outcome of this work offers mechanistic insights into atom-efficient conversion of bioderived oxygenates to renewable chemicals.