The role of oxophilic Mo species in Pt/MgO catalysts as extremely active sites for enhanced hydrodeoxygenation of dibenzofuran. Issue 9 (17th April 2020)

• Record Type: Journal Article
• Authors: Zhang, Jie; Zhao, Chengcheng; Li, Chuang; Li, Shenggang; Tsang, Chi-Wing; Liang, Changhai
• Is Part Of: Catalysis science & technology. Volume 10:Issue 9(2020)
• Page Start: 2948
• Page End: 2960
• Publication Date: 2020-04-17
• Subjects: Catalysis -- Periodicals; 541.395
• DOI: 10.1039/d0cy00341g
• Languages: English
• ISSNs: 2044-4753

Abstract

Abstract : The catalytic performance of the selective hydrodeoxygenation of dibenzofuran can be controlled by the MoO x surface density and varied with the increased MoO x surface density in a volcano-shape manner. Abstract : Pt/MoO x /MgO catalysts were prepared with varying Mo coverage and studied for the selective hydrodeoxygenation (HDO) of dibenzofuran (DBF) to biphenyl (BP), aiming at the elucidation of active sites for HDO. Oxophilic Mo species enrich the reducibility of surface Pt and the acidic sites of catalysts, change the product selectivity and then lead to significant improvement of the deoxygenation activity with an excellent HDO reaction rate (1.06 μmol s −1 g −1 ) on Pt/7MoO x /MgO compared with that (0.04 μmol s −1 g −1 ) on Pt/MgO. Moreover, the catalytic performance can be controlled by the MoO x surface density and varied with the increased MoO x surface density in a volcano-shape manner, in which at low Mo coverage (<2.27 Mo per nm 2 ), dispersed Mo species are dominant attributed to the active sites, and at further higher Mo coverage (>6.19 Mo per nm 2 ), crystalline MoO3 particulates may form that is detrimental to the activity. The highest BP yield (100%) was obtained with Pt/7MoO x /MgO close to Mo coverage of one monolayer. Furthermore, reactivity studies in combination with density functional theory (DFT) calculations for the adsorption of dibenzofuran and H2 indicate the synergy of Pt species in affording hydrogen species and adjacent MoO x species in adsorbing/activating C–O bonds suitable for the HDO of DBF.