Origin of strong metal-support interactions between Pt and anatase TiO2 facets for hydrodeoxygenation of m-cresol on Pt/TiO2 catalysts.

[Display omitted] • The strong metal-support interaction (SMSI) of Pt/TiO 2 is dependent on TiO 2 facet. • The order of encapsulation degree is Pt/TiO 2 -100 > Pt/TiO 2 -001 > Pt/TiO 2 -101. • Encapsulation correlates well with reduction degree of TiO 2 and location of oxygen vacancy. • The highest reaction rate and turnover frequency were achieved on Pt/TiO 2 -001. Metal/reducible metal oxide catalysts are widely used in hydrodeoxygenation (HDO) reactions for upgrading bio-oil to produce chemicals and fuel components. Under such strong reducing condition, the strong metal-support interaction (SMSI) should take place, however, few work has been devoted to understand the effect of facet of metal oxide on the SMSI and its consequence on HDO performance. Herein, Pt supported on anatase TiO 2 with varying dominative exposed facets of (1 0 1), (1 0 0) and (0 0 1) were prepared and tested in HDO of m-cresol at 350 °C and atmosphere H 2 pressure. The degree of SMSI of Pt/TiO 2 is strongly dependent on the facet of TiO 2 when reduced at 350 °C, and the degree of encapsulation decreases following the order of Pt/TiO 2 -100 > Pt/TiO 2 -001 > Pt/TiO 2 -101. The encapsulation correlates well with the reduction degree of TiO 2 and the location of oxygen vacancy, which are resulted from varied oxygen vacancy formation and anisotropic diffusion rates in different facets. The intermediate SMSI is achieved on TiO 2 -001, which creates the maximal density of Pt-O v -Ti3+ sites at the interfacial perimeter of TiO x /Pt for deoxygenation of m-cresol, resulting in the highest reaction rate and turnover frequency (TOF) while the lowest activation energy (E a). In contrast, the maximum SMSI on TiO 2 -100 leads to the lowest deoxygenation rate while the highest E a. This work provides insight into facet dependent SMSI of Pt/TiO 2 and indicates the HDO activity can be finely tailored by tuning the facet of TiO 2. [ABSTRACT FROM AUTHOR]