Ultradispersed Mo/TiO<sub>2</sub>catalysts for CO<sub>2</sub>hydrogenation to methanol

Len, Thomas; Bahri, Mounib; Ersen, Ovidiu; Lefkir, Yaya; Cárdenas, Luis; Villar‐García, Ignacio J.; Dieste, Virginia Pérez; Llorca, Jordi; Perret, Noémie; Checa, Ruben; Puzenat, E.; Afanasiev, P.; Morfin, F.; Piccolo, L.

doi:10.1039/d1gc01761f

Cited by 30 publications

(39 citation statements)

References 91 publications

(84 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Based on the catalyst characterization studies in combination with the selectivity patterns for the catalysts with different Mo loadings and literature precedents, a mechanism is proposed for guaiacol demethoxylation on MoO 3 /TiO 2 catalysts (Figure 11). It assumes that H 2 is adsorbed on particularly reduced MoO x species and dissociates to provide chemisorbed hydrogen [48,49] . Subsequent reaction of the latter with surface TiO 2 creates Ov I sites on the TiO 2 support Guaiacol is activated at these sites and demethoxylated to form phenol.…”

Section: Resultsmentioning

confidence: 99%

“…performed studies on Ag/TiO 2 as a demethoxylation catalyst and proposed that Ov are formed by the reduction of the TiO 2 surface by spillover hydrogen [21] . Like Ag, reduced MoO x species can activate hydrogen and produce spillover hydrogen to reduce the surface of the TiO 2 support [48,49] . However, oxygen vacancies may also be present on the MoO x crystallites by partial reduction of MoO 3 [14] .…”

Section: Resultsmentioning

confidence: 99%

“…[21] Like Ag, reduced MoO x species can activate hydrogen and produce spillover hydrogen to reduce the surface of the TiO 2 support. [48,49] However, oxygen vacancies may also be present on the MoO x crystallites by partial reduction of MoO 3 . [14] This is also confirmed by the TPR data for the catalyst samples, particularly at high Mo loading, see Figure S4 for details.…”

Section: S Betmentioning

confidence: 99%

“…It assumes that H 2 is adsorbed on particularly reduced MoO x species and dissociates to provide chemisorbed hydrogen. [48,49] Subsequent reaction of the latter with surface TiO 2 creates Ov I sites on the TiO 2 support Guaiacol is activated at these sites and demethoxylated to form phenol. It was found that particularly weak and medium acidic sites play a role and have a positive effect on the selectivity.…”

Section: Mechanistic Implicationsmentioning

confidence: 99%

See 3 more Smart Citations

Selective Demethoxylation of Guaiacols to Phenols using Supported MoO₃ Catalysts

et al. 2022

View full text Add to dashboard Cite

Lignin‐derived monomers with methoxy substituents are abundantly present in bioliquids derived from lignocellulosic biomass. Examples are the products obtained from the reductive catalytic fractionation of lignin (RCF) and pyrolysis of lignocellulosic biomass and hydrotreated products thereof. An attractive valorization step for these liquids involves demethoxylation to obtain alkylated phenols through selective catalytic hydrodeoxygenation (HDO). Within the context of sustainable chemistry, there is a strong drive to use cheap, non‐precious metal catalysts for this purpose. In this study, the HDO of guaiacol (5 wt% in toluene) was investigated in a continuous fixed‐bed reactor at 380 °C, 20 bar over supported MoO3 catalysts. MoO3 (5 %) supported on TiO2 (P25) was shown to give superior performance compared with MoO3 supported on anatase TiO2, Al2O3, SiO2, Nb2O5, CeO2, and ZrO2. Additional studies involving variation of the Mo loading and process conditions were performed, and the highest selectivity to demethoxylated phenolics like phenol and methylated phenols was 82 % at 97 % conversion of guaiacol. Both 4‐n‐propylguaiacol and a realistic guaiacols‐rich feed isolated from a representative pyrolysis oil were also successfully demethoxylated with the 5 % MoO3/TiO2 catalyst.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: S Betmentioning

confidence: 99%

Section: Mechanistic Implicationsmentioning

confidence: 99%

See 2 more Smart Citations

Selective Demethoxylation of Guaiacols to Phenols using Supported MoO₃ Catalysts

et al. 2022

View full text Add to dashboard Cite

show abstract

“…Piccolo's group evaluated several Mo‐modified commercial TiO 2 for methanol synthesis. [ 30 ] Rutile‐type samples (trade name: RNR, RL11A) had better methanol selectivity than anatase (trade name: PC500, DT51D) or their mixture (trade name: P25, P90), which was related to the nature of supported Mo (Figure 5f–h). Decreasing oxidation state was observed from anatase to rutile and most Mo ions were reduced to +4 or +5 valence.…”

Section: Catalysts For Co2 Activationmentioning

confidence: 99%

Recent Progress in Thermal Conversion of CO₂ via Single‐Atom Site Catalysis

Wang

Zheng

et al. 2022

Small Structures

View full text Add to dashboard Cite

CO2 emission has been an international issue of great concern. Utilizing of CO2, especially converting it to value‐added products, is widely investigated, among which the thermal conversion of CO2 has enormous potential for industry. Researches on single‐atom site catalysis (SAC) have become increasingly systematic during the last years. High performance and distinctive selectivity that SAC exhibits attribute to the isolated structure a large extent. To understand the structure–performance relationship of SAC in CO2 activation, issues including substrate, active components, coordination, chemical structure, etc. are of the essence not only in academia but also in industry. However, it is far away from the vision that the synthetic procedure and reaction pathway are deeply comprehended, thereupon precise single‐atom sites with specific structure are constructed and elementary reactions are regulated at will. Still a lot of efforts are needed to this field. Herein, CO2 reduction reactions are reviewed according to the products, and then catalysts are introduced by the substrate. The promoter, stability, synthesis/regeneration, characterization, and theory calculation issue related to SAC and CO2 activation are comprehensively summarized and discussed. Looking back the progress, challenge and outlook of single‐atom site catalysis are also proposed.

show abstract

Hybrid Catalyst Coupling Zn Single Atoms and CuN_x Clusters for Synergetic Catalytic Reduction of CO₂

Liu

et al. 2023

Adv Funct Materials

View full text Add to dashboard Cite

Reverse water-gas shift (RWGS) reaction is the initial and necessary step of CO 2 hydrogenation to high value-added products, and regulating the selectivity of CO is still a fundamental challenge. In the present study, an efficient catalyst (CuZnN x @C-N) composed by Zn single atoms and Cu clusters stabilized by nitrogen sites is reported. It contains saturated four-coordinate Zn-N 4 sites and low valence CuN x clusters. Monodisperse Zn induces the aggregation of pyridinic N to form Zn-N 4 and N 4 structures, which show strong Lewis basicity and has strong adsorption for *CO 2 and *COOH intermediates, but weak adsorption for *CO, thus greatly improves the CO 2 conversion and CO selectivity. The catalyst calcined at 700 °C exhibits the highest CO 2 conversion of 43.6% under atmospheric pressure, which is 18.33 times of Cu-ZnO and close to the thermodynamic equilibrium conversion rate (49.9%) of CO 2 . In the catalytic process, CuN x not only adsorbs and activates H 2 , but also cooperates with the adjacent Zn-N 4 and N 4 structures to jointly activate CO 2 molecules and further promotes the hydrogenation of CO 2 . This synergistic mechanism will provide new insights for developing efficient hydrogenation catalysts.

show abstract

Ultradispersed Mo/TiO₂catalysts for CO₂hydrogenation to methanol

Abstract: Mo/TiO2 catalysts with atomic dispersion of molybdenum appear active and stable in the gas-phase hydrogenation of CO2. The comparison between various titania materials shows a crucial effect of the support...

Cited by 30 publications

References 91 publications

Selective Demethoxylation of Guaiacols to Phenols using Supported MoO₃ Catalysts

Selective Demethoxylation of Guaiacols to Phenols using Supported MoO₃ Catalysts

Recent Progress in Thermal Conversion of CO₂ via Single‐Atom Site Catalysis

Hybrid Catalyst Coupling Zn Single Atoms and CuN_x Clusters for Synergetic Catalytic Reduction of CO₂

Contact Info

Product

Resources

About

Ultradispersed Mo/TiO2catalysts for CO2hydrogenation to methanol

Abstract: Mo/TiO2 catalysts with atomic dispersion of molybdenum appear active and stable in the gas-phase hydrogenation of CO2. The comparison between various titania materials shows a crucial effect of the support...

Cited by 30 publications

References 91 publications

Selective Demethoxylation of Guaiacols to Phenols using Supported MoO3 Catalysts

Selective Demethoxylation of Guaiacols to Phenols using Supported MoO3 Catalysts

Recent Progress in Thermal Conversion of CO2 via Single‐Atom Site Catalysis

Hybrid Catalyst Coupling Zn Single Atoms and CuNx Clusters for Synergetic Catalytic Reduction of CO2

Contact Info

Product

Resources

About

Ultradispersed Mo/TiO₂catalysts for CO₂hydrogenation to methanol

Selective Demethoxylation of Guaiacols to Phenols using Supported MoO₃ Catalysts

Selective Demethoxylation of Guaiacols to Phenols using Supported MoO₃ Catalysts

Recent Progress in Thermal Conversion of CO₂ via Single‐Atom Site Catalysis

Hybrid Catalyst Coupling Zn Single Atoms and CuN_x Clusters for Synergetic Catalytic Reduction of CO₂