HZSM-5 zeolites containing impurity iron species for the photocatalytic reduction of CO<sub>2</sub> with H<sub>2</sub>O

Tong, Yuecong; Zhang, Yingguang; Tong, Na; Zhang, Zizhong; Wang, Ying; Zhang, Xiaoyan; Zhu, Shengli; Li, Fuying; Wang, Xuxu

doi:10.1039/c6cy01237j

Cited by 38 publications

(29 citation statements)

References 42 publications

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“…According to spectroscopic studies of the zeolite ZSM-5, only iron species in different states originate bands in the 200À500 nm (6.19-2.48 eV) range and iron is unavoidable in synthetic zeolites. 12 So as mentioned in the previous subsection, the iron species in the synthetic zeolites possibly contribute to absorption in the weak bands of Fig. 4, despite the low iron content: 0.04 wt% in C, 0.07 wt% in M, and 0.01% in SH.…”

Section: Experimental Band Gap Energy Of Synthetic Clinoptilolite Andmentioning

confidence: 70%

“…In the absence of a photogenerated electron-hole pair, a charge-transfer excited state in an oxygen-bonded metal impurity or another active site may be responsible for a photoreaction. In the rst case, Anpo and other authors [11][12][13]20 have veried the function of transition metal impurities and in the second case, Kato 50 and Wang et al 22 attributed photoactivity of ZSM5 to highly isolated framework Al-O units interacting with no metal cations. In our case, the values of k 0 in Table 1 correlate poorly with the ratio Fe/ Al (R 2 ¼ 0.52) and with the aluminium percent (R 2 ¼ 0.69).…”

Section: Correlation Of Photoactivity With Zeolites Compositionmentioning

confidence: 99%

“…This nding is not consistent with the results found mainly with the synthetic zeolite Fe-ZSM-5 when it contained trace quantities (0.043 wt%) of iron impurities 13,20 or framework iron deliberately introduced up to values of 0.089 wt% Fe. 12 The authors found that the rate of photocatalytic reactions in the gas phase depended linearly on the concentration of the iron species in the zeolite, which acted as photoactive centres excited by UV light to form a charge-transfer excited state. The nature of iron species is complex.…”

Section: Correlation Of Photoactivity With Zeolites Compositionmentioning

confidence: 99%

“…It shows that despite the low iron content (0.1 wt%), as reported, it is sufficient to generate a photoexcited charge-transfer effect and a photoreaction. 12,13,20,48 It would also be an indirect indication of the presence of framework iron. 20 In contrast, NFe with high iron concentration (1.6 wt% Fe ¼ 1.2 framework + 0.4 ironexchanged iron) presents a similar value of k obs (Table 1) as the synthetic SH reecting the lack of access to all framework photoactive sites of NFe.…”

Section: Correlation Of Photoactivity With Zeolites Compositionmentioning

confidence: 99%

“…9,10 Relevant research on zeolite-based photocatalysts has been devoted mainly to synthetic powdered zeolites and gas phase reactions. 11,12 Authors focused their attention on the effect of both Ti and Fe species as impurities or on what has been called photoactive single sites implanted in the zeolitic structure. [10][11][12][13][14][15][16][17] Although much important work has been carried out on the siliceous materials (MCM41, 18 silicalite 19 ) and zeolitic catalysts such as NaA, faujasite, 10 mordenite, 10 and HZSM-5, 12,13,17,[20][21][22] the photoactivity of neat natural zeolites has rarely been explored before.…”

Section: Introductionmentioning

confidence: 99%

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Unpredicted photocatalytic activity of clinoptilolite–mordenite natural zeolite

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Section: Experimental Band Gap Energy Of Synthetic Clinoptilolite Andmentioning

confidence: 70%

Section: Correlation Of Photoactivity With Zeolites Compositionmentioning

confidence: 99%

Section: Correlation Of Photoactivity With Zeolites Compositionmentioning

confidence: 99%

Section: Correlation Of Photoactivity With Zeolites Compositionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Applications of Zeolites to C1 Chemistry: Recent Advances, Challenges, and Opportunities

2020

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However, due to growing concerns regarding crude oil depletion and increasing environmental requirements, finding abundant fossil hydrocarbons with high H 2 /C ratios as well as alternative carbon resources has become crucial to maintaining sustainable, environmentally benign systems that can aid human development. [2] Thus, one-carbon (C1) chemistry, which is the chemistry of C1 molecules that can be derived from sources other than fossil hydrocarbons, including carbon monoxide (CO), carbon dioxide (CO 2), methane (CH 4), methanol (CH 3 OH), and formic acid (HCOOH), has emerged and plays important roles in the energy supply and high-value chemical preparation. [1,3] These C1 resources can be obtained from natural gas, shale gas, coal, biomass, solid wastes, and CO 2 emissions. [3a,4] Extensive studies have been dedicated to the catalytic conversion of C1 molecules, including production of dimethyl ether (DME) and liquid fuels from syngas (a mixture of CO and H 2); production of methanol, light olefins, and even aromatics from CH 4 ; and production of hydrogen from HCOOH. [5] All of these transformations require metallic catalytic species such as single atoms; clusters; or oxides, carbides, or alloy particles (e.g., Rh-, AuPd-, Fe 3 O 4-, and Fe 5 C 2-based catalysts). However, these isolated metallic species suffer from severe sintering due to a lack of confinement effects from supports, which leads to poor catalytic stability and decreased selectivities toward their target products. The efficient production of a specific range of hydrocarbons or oxygenates remains a difficult scientific and technical challenge. Overcoming product selectivity limitations and improving catalyst stabilities via catalyst designs are important areas of research. Zeolites are an important class of shape-selective catalysts with uniform micropores, tunable acidities, and high thermal and hydrothermal stabilities. Over the past decade, they have gained broad popularity and been applied to various industrially important catalytic processes. [6] In particular, the design and development of zeolite-based mono-, bi-, and multifunctional catalysts that combine the advantages of zeolites with those of metallic catalytic species have boosted the application of zeolites to C1 chemistry. As shown in Figure 1, value-added hydrocarbons and oxygenates can be produced from C1 molecules via various catalytic routes over zeolite-based catalysts. By May of 2020, the Structure Commission of the International C1 chemistry, which is the catalytic transformation of C1 molecules including CO, CO 2 , CH 4 , CH 3 OH, and HCOOH, plays an important role in providing energy and chemical supplies while meeting environmental requirements. Zeolites are highly efficient solid catalysts used in the chemical industry. The design and development of zeolite-based mono-, bi-, and multifunctional catalysts has led to a booming application of zeolite-based catalysts to C1 chemistry. Combining the advantages of zeolites and metallic catalytic species has promoted the catal...

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Catalytic Conversion of CO₂ to Cyclic Carbonates through Multifunctional Zinc‐Modified ZSM‐5 Zeolite

et al. 2018

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The production of fine chemicals using CO2 as C1 building block through inexpensive heterogeneous catalysts with high efficiency under low pressure is challenging. Herein we propose for the first time the utilization of a multifunctional heterogeneous zinc‐modified HZSM‐5 (ZnHZSM‐5) catalyst for upgrading CO2 by incorporation into cyclic carbonates from CO2 and epoxides. Owing to the nice surface properties such as abundant Lewis acid, Brønsted acid and Lewis base sites, large surface area, and plenty of micropores, CO2 could be concentrated and well activated in ZnHZSM‐5 verified by CO2‐TPD, TG‐MS, etc. Meanwhile, the epoxides were also activated through metal center and hydrogen bond. Therefore, the reaction can easily assemble at the catalyst interface and show exceptional performance, affording the aimed products with high yield of up to 99% in the presence of commercial tetra‐n‐propylammonium bromide (90% in kilogram scale with 0.004 mol% ZnHZSM‐5 and 0.015 mol% nPr4NBr).

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HZSM-5 zeolites containing impurity iron species for the photocatalytic reduction of CO₂ with H₂O

Abstract: The impurity [Fe3+–O2−] species in HZSM-5 zeolite is predominantly tetrahedrally coordinated and is the photoactive centre for photocatalytic CO2 conversion.

Cited by 38 publications

References 42 publications

Unpredicted photocatalytic activity of clinoptilolite–mordenite natural zeolite

Unpredicted photocatalytic activity of clinoptilolite–mordenite natural zeolite

Applications of Zeolites to C1 Chemistry: Recent Advances, Challenges, and Opportunities

Catalytic Conversion of CO₂ to Cyclic Carbonates through Multifunctional Zinc‐Modified ZSM‐5 Zeolite

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HZSM-5 zeolites containing impurity iron species for the photocatalytic reduction of CO2 with H2O

Abstract: The impurity [Fe3+–O2−] species in HZSM-5 zeolite is predominantly tetrahedrally coordinated and is the photoactive centre for photocatalytic CO2 conversion.

Cited by 38 publications

References 42 publications

Unpredicted photocatalytic activity of clinoptilolite–mordenite natural zeolite

Unpredicted photocatalytic activity of clinoptilolite–mordenite natural zeolite

Applications of Zeolites to C1 Chemistry: Recent Advances, Challenges, and Opportunities

Catalytic Conversion of CO2 to Cyclic Carbonates through Multifunctional Zinc‐Modified ZSM‐5 Zeolite

Contact Info

Product

Resources

About

HZSM-5 zeolites containing impurity iron species for the photocatalytic reduction of CO₂ with H₂O

Catalytic Conversion of CO₂ to Cyclic Carbonates through Multifunctional Zinc‐Modified ZSM‐5 Zeolite