Rational Design of a Bifunctional Catalyst for the Oxydehydration of Glycerol: A Combined Theoretical and Experimental Study

Abstract

Due to its cost effectiveness and eco-friendliness, oxydehydration of glycerol is currently attracting considerable attentions. In an attempt to develop efficient catalyst for the reaction, tungsten incorporated molybdenum vanadium mixed oxide (MoVW) catalysts were designed based on computational calculations and mechanistic insights. By incorporating tungsten into molybdenum vanadium mixed oxide structure, the catalysts are active and selective not only for the dehydration of glycerol but also the subsequent oxidation of acrolein to acrylic acid. Through DFT calculations, we confirmed that tungsten species induced change in electron density of neighboring atoms, which leads to selective production of acrylic acid. Structural characterization demonstrates that the structure of such MoVW catalysts is similar to that of DFT models. The incorporated tungsten species enhanced the acid and redox properties of the catalyst, leading to high selectivity for acrylic acid (30.5%). It not only induced but also stabilized the reduced oxidation states of molybdenum and vanadium atoms, as confirmed by XPS and DFT calculations. Hence, a stable and selective production of acrylic acid was achieved with full glycerol conversion for 110 h. MoVW catalytic system with an additional acid catalyst bed exhibited remarkable selectivity for acrylic acid (47.2%), suggesting its potential for practical applications.

Structure–Reactivity Correlations in Vanadium‐Containing Catalysts for One‐Pot Glycerol Oxidehydration to Acrylic Acid

“…Overall, catalysts related to metal-oxide bronzes seem to be the best-performing materials, and they are capable of efficiently transforming glyceroli nto acrylic acid with yields > 50 % and productivities of industrial relevance. Ta king into account the lack of molecular-level information on the one-pot oxidehydration reaction of glycerol, that only recently startedt ob ef ulfilled, [25] we presenth erein an in-depth study that aimed to link the results obtained by reactivity tests performed in af low reactor with those obtained by in situ FTIR spectroscopy studies by using the reaction intermediate (i.e., acrolein), as well as Xray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy,t emperature-programmed reduction and temperature-programmed desorption of ammonia mass spectrometry( NH 3 -TPD-MS). [22,23] Interestingly,t he commonp oint of all these catalytic systemsi st he presence of vanadium as one of the main (or only) redoxe lements;h owever,d espite this leitmotif, the catalytic behavioro ft hese mixed oxides is fairly different.…”

“…The environment that characterizes the vanadium contour in the differentc atalytic systems makes it possible to forge its properties, weakening some of them in favor of others. Ta king into account the lack of molecular-level information on the one-pot oxidehydration reaction of glycerol, that only recently startedt ob ef ulfilled, [25] we presenth erein an in-depth study that aimed to link the results obtained by reactivity tests performed in af low reactor with those obtained by in situ FTIR spectroscopy studies by using the reaction intermediate (i.e., acrolein), as well as Xray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy,t emperature-programmed reduction and temperature-programmed desorption of ammonia mass spectrometry( NH 3 -TPD-MS). Representative multifunctional V-containing catalysts were considered:o ne, hexagonal tungsten bronzes( HTBs) with in-framework or extra-framework vanadium species; two, zeotype materials, that is, modified-AlPO 4 -5 catalysts [26] with in-framework and extra-framework vanadium species; three, ac ommercial vanadyl pyrophosphate (VPP) catalyst.…”

Navigating Glycerol Conversion Roadmap and Heterogeneous Catalyst Selection Aided by Density Functional Theory: A Review

“…Moreover, Yun et al [124] used DFT calculations to design W-incorporated MoVW mixed oxide catalysts for glycerol oxydehydration to obtain acrylic acid, acrolein, acetic acid, along with CO 2 and acetaldehyde. It is revealed that the incorporated W species are able to induce neighboring Mo, V, and O, to a reduced state for Mo and V (e.g., Mo 5+ and V 4+ ), and those more nucleophilic O, which are necessary for selective acrylic acid production.…”

Insights into the Li Diffusion Dynamics and Nanostructuring of H2Ti12O25 To Enhance Its Li Storage Performance

“…The difference in charge densities during Li migration was calculated using the following equation: Δρ = ρLiTiO − (ρTiO + ρLi) where ρLiTiO is the total charge density of the LiTiO system, and ρTiO and ρLi are the charge densities of the TiO systems without Li and isolated Li atoms. 26,27 ■ RESULTS AND DISCUSSION To use an in-depth kinetic study of Li to accurately explain the limitations associated with the electrochemical properties of 28 The optimized structure and coordinates are presented in Figure S3.…”