Combining X-ray Diffraction and X-ray Absorption Spectroscopy to Unveil Zn Local Environment in Zn-Doped ZrO<sub>2</sub> Catalysts

Salusso, Davide; Borfecchia, Elisa; Bordiga, Silvia

doi:10.1021/acs.jpcc.1c06202

Cited by 17 publications

(25 citation statements)

References 51 publications

(141 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For ZnO and Zn x Zr 1– x O 2– x , a peak at 1.8 Å appears and corresponds to the first-nearest neighbor Zn–O distance (1.9–2.0 Å). The peak at 2.9 Å is related to the first- and second-nearest neighbor Zn–Zn distances of the zinc oxides (3.2 Å and 3.7 Å) . Note that the RSF of ZnZr07 does not have the Zn–Zn peak, which means that the Zn species in ZnZr07 contain isolated [ZnO a ] clusters.…”

Section: Resultsmentioning

confidence: 99%

“…Further increasing the Zn content does not increase the number of active sites but only increases the number of other sites with low activity. Based on previous reports, we introduced three types of Zn-containing active sites as follows: (1) Zn–O–Zr sites, ,,, (2) interfacial sites between ZnO and ZrO 2 , and (3) interfacial sites between amorphous ZnO and ZrO 2 Figure shows the turnover frequencies of methanol (TOF CH3OH ) for Zn x Zr 1– x O 2– x .…”

Section: Resultsmentioning

confidence: 99%

“…Many researchers have developed metal oxide catalysts with high activity in and selectivity for methanol. The following active species on metal oxide catalysts have been reported: Zn, ,− Ga, , Cd, In, , and Cr . The combination of Zn and Zr was found to be the optimal mix of cationic components for the catalyst. , Thus, Zn x Zr 1– x O 2– x is promising as a metal oxide catalyst for CO 2 -to-methanol hydrogenation.…”

Section: Introductionmentioning

confidence: 97%

“…Here, three types of active sites are proposed. The first is Zn–O–Zr sites, which are essential to CO 2 hydrogenation because Zn 2+ is readily incorporated into the ZrO 2 lattice. ,,, The second is ZnO nanoparticles, which are embedded on the ZrO 2 surface and have interfacial sites that can effectively hydrogenate CO 2 to methanol . The third is activated amorphous ZnO, which boosts the methanol formation rate by promoting the activation of H 2 …”

Section: Introductionmentioning

confidence: 99%

“…10,25,26,29 The second is ZnO nanoparticles, which are embedded on the ZrO 2 surface and have interfacial sites that can effectively hydrogenate CO 2 to methanol. 28 The third is activated amorphous ZnO, which boosts the methanol formation rate by promoting the activation of H 2 . 30 This study aimed to clarify the structure of the specific active sites for CO 2 -to-methanol hydrogenation over Zn x Zr 1-x O 2-x .…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Active Sites on Zn_xZr_1–xO_2–x Solid Solution Catalysts for CO₂-to-Methanol Hydrogenation

et al. 2022

View full text Add to dashboard Cite

Recently, Zn x Zr1–x O2–x catalysts have attracted attention as next-generation CO2-to-methanol hydrogenation catalysts. In this study, we examined the effect of the Zn content on CO2-to-methanol hydrogenation over Zn x Zr1–x O2–x catalysts and determined the active-site structure through both calculations and experiments. When the Zn content was low, Zn x Zr1–x O2–x contained Zn clusters (isolated [ZnO a ] clusters and [Zn b O c ] oligomers). The presence of clusters indicates the formation of Zn–O–Zr sites. Interestingly, our calculations revealed that the Zn species in the clusters are easily exposed on the Zn x Zr1–x O2–x surface. This result is in line with the experimental results, suggesting that Zn species were unevenly distributed on the Zn x Zr1–x O2–x surface and deposited near the surface. The addition of excess Zn to ZrO2 led to the formation of both Zn-containing clusters and ZnO nanoparticles. During the reactions, the Zn–O–Zr sites derived from the clusters showed specific activity for CO2-to-methanol hydrogenation. Understanding the active-site structure will lead to the future development of Zn x Zr1–x O2–x catalysts.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Active Sites on Zn_xZr_1–xO_2–x Solid Solution Catalysts for CO₂-to-Methanol Hydrogenation

et al. 2022

View full text Add to dashboard Cite

show abstract

Design of Flame‐Made ZnZrO_x Catalysts for Sustainable Methanol Synthesis from CO₂

Araújo

Morales‐Vidal

Zou

et al. 2023

Advanced Energy Materials

View full text Add to dashboard Cite

Mixed zinc‐zirconium oxides, ZnZrOx, are highly selective and stable catalysts for CO2 hydrogenation to methanol, a pivotal energy vector. However, their activity remains moderate, and descriptors to design improved systems are lacking. This work applies flame spray pyrolysis (FSP), a one‐step and scalable method, to synthesize a series of ZnZrOx catalysts, and systematically compares them to coprecipitated (CP) analogs to establish deeper synthesis–structure–performance relationships. FSP systems (up to 5 mol%) generally display a threefold higher methanol productivity compared to their CP counterparts. In‐depth characterization and theoretical simulations show that, unlike CP, FSP maximizes the surface area and formation of atomically dispersed Zn2+ sites incorporated in lattice positions within the ZrO2 surface, which is key to improving performance. Analysis by in situ electron paramagnetic resonance (EPR) spectroscopy reveals that the specific architecture of the flame‐made catalyst markedly fosters the generation of oxygen vacancies. Together with surrounding Zn and Zr‐O atoms, the oxygen vacancies create active ensembles that favor methanol formation through the formate path while suppressing undesired CO production, as confirmed by kinetic modeling. This study elucidates the nature of active sites and their working mechanism, pushing forward ZnZrOx‐catalyzed methanol synthesis by providing a new benchmark for this cost‐effective and earth‐abundant catalyst family.

show abstract

Unlocking a Dual‐Channel Pathway in CO₂ Hydrogenation to Methanol over Single‐Site Zirconium on Amorphous Silica

Yang,

Yu,

Zimina

et al. 2023

Angewandte Chemie

View full text Add to dashboard Cite

Converting CO2 into methanol on a large scale is of great significance in the sustainable methanol economy. Zirconia species are considered to be an essential support in Cu‐based catalysts due to their excellent properties for CO2 adsorption and activation. However, the evolution of Zr species during the reaction and the effect of their structure on the reaction pathways remain unclear. Herein, single‐site Zr species in an amorphous SiO2 matrix are created by enhancing the Zr−Si interaction in Cu/ZrO2‐SiO2 catalysts. In situ X‐ray absorption spectroscopy (XAS) reveals that the coordination environment of single‐site Zr is sensitive to the atmosphere and reaction conditions. We demonstrate that the CO2 adsorption occurs preferably on the interface of Cu and single‐site Zr rather than on ZrO2 nanoparticles. Methanol synthesis in reverse water‐gas‐shift (RWGS)+CO‐hydro pathway is verified only over single‐dispersed Zr sites, whereas the ordinary formate pathway occurs on ZrO2 nanoparticles. Thus, it expands a non‐competitive parallel pathway as a supplement to the dominant formate pathway, resulting in the enhancement of Cu activity sixfold and twofold based on Cu/SiO2 and Cu/ZrO2 catalysts, respectively. The establishment of this dual‐channel pathway by single‐site Zr species in this work opens new horizons for understanding the role of atomically dispersed oxides in catalysis science.

show abstract

Combining X-ray Diffraction and X-ray Absorption Spectroscopy to Unveil Zn Local Environment in Zn-Doped ZrO₂ Catalysts

Cited by 17 publications

References 51 publications

Active Sites on Zn_xZr_1–xO_2–x Solid Solution Catalysts for CO₂-to-Methanol Hydrogenation

Active Sites on Zn_xZr_1–xO_2–x Solid Solution Catalysts for CO₂-to-Methanol Hydrogenation

Design of Flame‐Made ZnZrO_x Catalysts for Sustainable Methanol Synthesis from CO₂

Unlocking a Dual‐Channel Pathway in CO₂ Hydrogenation to Methanol over Single‐Site Zirconium on Amorphous Silica

Contact Info

Product

Resources

About

Combining X-ray Diffraction and X-ray Absorption Spectroscopy to Unveil Zn Local Environment in Zn-Doped ZrO2 Catalysts

Cited by 17 publications

References 51 publications

Active Sites on ZnxZr1–xO2–x Solid Solution Catalysts for CO2-to-Methanol Hydrogenation

Active Sites on ZnxZr1–xO2–x Solid Solution Catalysts for CO2-to-Methanol Hydrogenation

Design of Flame‐Made ZnZrOx Catalysts for Sustainable Methanol Synthesis from CO2

Unlocking a Dual‐Channel Pathway in CO2 Hydrogenation to Methanol over Single‐Site Zirconium on Amorphous Silica

Contact Info

Product

Resources

About

Combining X-ray Diffraction and X-ray Absorption Spectroscopy to Unveil Zn Local Environment in Zn-Doped ZrO₂ Catalysts

Active Sites on Zn_xZr_1–xO_2–x Solid Solution Catalysts for CO₂-to-Methanol Hydrogenation

Active Sites on Zn_xZr_1–xO_2–x Solid Solution Catalysts for CO₂-to-Methanol Hydrogenation

Design of Flame‐Made ZnZrO_x Catalysts for Sustainable Methanol Synthesis from CO₂

Unlocking a Dual‐Channel Pathway in CO₂ Hydrogenation to Methanol over Single‐Site Zirconium on Amorphous Silica