ChemCatChem
·
2024
·
IF 3.8
Huan Yang,Xu Wang,Haowei Wang,Ya-Dong Xie,An-Hui Lu
Graphical The Sn species doped by coprecipitation with Al precursor introduces additional acidic sites on Sn-doped alumina, which after loading with Pt species exhibits superior reactivity and stability for propane dehydrogenation. Alumina-supported PtSn catalysts have been industrialized as the major catalysts for propane dehydrogenation, where Sn serves as an essential promoter. Herein, we synthesized a variety of Sn-doped alumina supports by regulating the precipitation order of Sn and Al precursors as follows: Sn precursor precipitated before Al, coprecipitated with Al, precipitated immediately after Al, or precipitates after 2 h of Al. The effect of Sn promoter on the surface acidic properties of alumina and, ultimately, on propane dehydrogenation was further investigated. The Sn species introduced by coprecipitation in alumina created additional surface strong acid sites, attributed to more Sn 4+ species on the surface, which are able to remain stable during the subsequent treatment. Consequently, the coprecipitated Sn species in the corresponding catalyst donate more electrons to Pt and reduce the metal particle size. As a result, the catalyst with Pt supported on the coprecipitated support (Sn+Al) exhibits superior initial propane conversion (43.2%) and stability ( k d = 0.035 h −1 ). This study provides new insight into the interaction between the two key components, tin promoter and alumina support, of Pt/Sn-Al 2 O 3 catalysts.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
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2019
·
IF 4.63
Haoren Wang,Huiwen Huang,Kashan Bashir,Chunyi Li
Tin oxide supported on silica (SnO 2 /SiO 2 ) were prepared by incipient-wetness impregnation method and examined for propane dehydrogenation at 600 °C. The physicochemical properties of SnO 2 /SiO 2 were characterized by N 2 -physisorption, XRD, UV–vis-DRS and H 2 -TPR. The results indicate that, at Sn loading ≤ 1.78 wt%, SiO 2 contains a uniform distribution of Sn as isolated species in tetrahedral coordination, while crystalline SnO 2 together with isolated Sn species are found for the higher Sn loadings. The reducibility of various Sn species was studied by a combination of XPS, H 2 -TPR, and reduction-reoxidation-TPR techniques. The results reveal that after high-temperature H 2 reduction, crystalline SnO 2 is fully reduced to metallic Sn, whereas isolated Sn are stabilized in the Sn 2+ state with high dispersion due to a strong interaction between isolated Sn and support. Catalytic activity tests showed that these Sn 2+ species exhibits both high activity and stability for propane dehydrogenation.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
RENEWABLE ENERGY
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2024
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IF 9
Hongjin Qu,Tianliang Lu,Xiaomei Yang,Lipeng Zhou
Tin-containing β zeolite exhibits excellent catalytic performance in various biomass conversions to high-value chemicals due to its strong Lewis (L) acidity produced by framework Sn 4+ sites. However, it is difficult to incorporate Sn species into the framework of β zeolite due to that the ionic radius of Sn (0.69 Å) is larger than that of Si (0.40 Å). Herein, organic additives with carbonyl, hydroxyl , aldehyde or amine groups were used to stabilize Sn species in the gel and framework Sn 4+ in the zeolite. Among all additives, acetone (AC) has the best stabilizing effect on Sn species. The stabilization effect between AC and Sn 4+ sites was observed by FT-IR. The characterization results indicate that more tin species were incorporated into β framework and the L acid density increased due to the complexation between carbonyl group and Sn species. Compared to Sn-β-3d synthesized without additive, the L acid density of Sn-β-AC-3d increased by ∼50% (from 21 μmol g −1 to 34 μmol g −1 ). For the conversion of ethyl levulinate to γ-valerolactone, the reaction reached equilibrium faster over Sn-β-AC-3d than over Sn-β-3d at the investigated reaction temperatures. A yield of 98% was obtained over Sn-β-AC-3d at 110 °C. Besides, Sn-β-AC-3d exhibited good stability and reusability.
研究领域:
催化化学
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生物质转化
✓ 已验证
产品关联
DOI
高影响因子
Nano Research
·
2020
·Vol. 14
·期 4
·1053-1060
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IF 8.183
Wu Jun,Bai Xue,Ren Zhiyu,Du Shichao,Song Ziehen,Zhao Lei,Liu Bowen,Wang Guiling,Fu Honggang
Although Sn-based catalysts have recently achieved considerable improvement in selective electro-catalyzing CO 2 into HCOOH, the role of various valence Sn species is not fully understood due to the complexity and uncertainty of their evolution during the reaction process. Here, inspired by the theoretical simulations that the concomitant multivalent Sn (Sn 0 , Sn 11 and Sn IV ) can significantly motivate the intrinsic activity of Sn-based catalyst, the Sn/SnO/SnO 2 nanosheets were proposed to experimentally verify the synergistic effect of multivalent Sn species on the CO 2 -into-HCOOH conversion. During CO 2 reduction reaction, the Sn/SnO/SnO 2 nanosheets, which are prepared by the sequential hydrothermal reaction, calcined crystallization and low-temperature H 2 treatment, exhibit a high FE HCOOH of 89.6% at −0.9 V RHE as well as a large cathodic current density. Systematic experimental and theoretical results corroborate that multivalent Sn species synergistically energize the CO 2 activation, the HCOO* adsorption, and the electron transfer, which make Sn/SnO/SnO 2 favour the conversion from CO 2 into HCOOH in both thermodynamics and kinetics. This proof-of-concept study establishes a relationship between the enhanced performance and the multivalent Sn species, and also provides a practicable and scalable avenue for rational engineering high-powered electrocatalysts.
研究领域:
电催化
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材料科学
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理论计算
✓ 已验证
产品关联
DOI
高影响因子
FOOD CHEMISTRY
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2024
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IF 8.5
Feng Guo,Pingxiu Zeng,Jinhua Liu,Hongmei Hu,Wenbin Zhu,Yuanchao Wang,Heyong Cheng
Tin and lead are a global concern considering their species-dependent toxicity, bioavailability and transformation. Simultaneous speciation analysis of tin and lead is challenging for a large food capacity containing unstable species. Herein, we developed two sensitive methods for rapid quantification of tin and lead species in Antarctic seafood by high-performance liquid chromatography and inductively coupled plasma mass spectrometry based on strong cation-exchange and Amphion columns. Inorganic tin and lead, four organotin and two organolead compounds can be analysed in 16 min on a 10-cm Amphion II column (mobile phase: 4 mM sodium dodecyl benzene sulfonate at pH 2.0) with 0.02–0.24 μg L –1 detection limits. The method was applied to Antarctic krill and fish, demonstrating the presence of any tin and lead species down to μg kg −1 level. Overall, the proposed methods are sensitive, efficient and environment-friendly for routine speciation analysis of tin and lead in food samples.
研究领域:
环境科学
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食品科学
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分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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