Modulating oxygen vacancies in Pt-WO<i>_x</i>-decorated MOF-74(Co) catalysts for the efficient conversion of glucose to 1,2-propanediol under mild conditions

Selective conversion of glucose to valuable 1,2-propanediol (1,2-PDO) has been a research priority, but the process often suffers from problems such as harsh reaction conditions. Therefore, the development of efficient catalysts for the efficient synthesis of 1,2-PDO from glucose under mild conditions is essential. Herein, we prepared Pt-WOx -metal-organic framework (MOF)-74(Co) catalysts by a simple two-step method, achieving a high yield of 52.9% of 1,2-PDO under milder conditions (160 °C, 0.2 MPa H2, 4 h), surpassing the majority of recent studies in this field. High-resolution transmission electron microscopy (HRTEM) revealed that Pt nanoparticles (~2.1 nm) and WOx species were uniformly dispersed within the structure of MOF-74(Co). The experimental results confirmed that MOF-74(Co) facilitated the isomerization of glucose into fructose, which then underwent further conversion to yield 1,2-PDO. In addition, X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR) and NH3 temperature-programmed desorption (NH3-TPD) results revealed that Pt-WOx -MOF-74(Co) has more oxygen vacancies to act as acidic sites. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) further confirmed the efficient conversion of glucose to intermediate and final products over Pt-WOx -MOF-74(Co). Furthermore, cycling experiments confirmed that Pt-WOx -MOF-74(Co) can be reused several times. This is the first report that MOFs can be employed as the catalyst support in facilitating glucose conversion to diols, which provides important guidance for using MOFs in biomass utilization in the future.