Identification of a Facile Pathway for Dioxymethylene Conversion to Formate Catalyzed by Surface Hydroxyl on TiO2-Based Catalyst

• DOI: 10.1021/acscatal.0c01901
• Publication Date: 2020-07-31T19:03:42Z
• Authors: Xueyan Chen; Guangzhi He; Yaobin Li; Min Chen; Xiaoxiao Qin; Changbin Zhang; Hong He
• Keywords: Noble metal; Reaction intermediate

Formaldehyde (HCHO) is either a reactant, intermediate, or product in numerous industrial catalytic reactions; therefore, revealing the full transformation process of HCHO during heterogeneous catalysis prime importance understanding mechanisms many HCHO-related reactions and designing more efficient catalysts. As two main intermediates transformation, conversion dioxymethylene (DOM) to formate one key steps. There are three recognized pathways for this step, including direct dissociation DOM, DOM combining with surface O, through Cannizzaro-type reaction. Herein, we reveal that reaction between abundant OH groups facile pathway species on TiO2 also TiO2-supported noble metal In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) results demonstrate presence water vapor favorable TiO2, loading metals (Ir/Pt) further promotes activation H2O, thereby boosting into formate. Density functional theory (DFT) calculations show consumes bridging form first followed by terminal produce formate, latter both thermodynamically kinetically favorable. These provide deeper insight another role hydroxyl