ChemCatChem
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2020
·Vol. 12
·期 15
·3880-3889
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IF 4.853
Xingling Zhao,Jun Xu,Yueying Chu,Guodong Qi,Qiang Wang,Wei Gao,Shenhui Li,Ningdong Feng,Feng Deng
Graphical Methane activation : Different types of Ga-CH 3 species were observed in methane activation on Ga-modified ZSM-5 zeolite, evidencing different pathways for heterolytic cleavage of C−H bond of methane. Two-dimensional solid-state NMR experiments provided detailed information on the location and local environment of the Ga-CH 3 species. Methane activation on Ga-modified ZSM-5 zeolites (Ga/ZSM-5) was studied by solid-state NMR spectroscopy. Two types of Ga species, namely highly dispersed oxides and cationic Ga species, were determined by 71 Ga QCPMG NMR. The activation of methane on Ga/ZSM-5 was explored by using 13 C and 1 H MAS NMR. Four types of Ga-CH 3 species along with Ga-OH groups were observed on Ga/ZSM-5, evidencing different pathways for heterolytic cleavage of C−H bond of methane. Two-dimensional (2D) 1 H- 1 H correlation NMR experiments provide detailed information on the location and local environment of the Ga-CH 3 species by correlating the protons in Ga-CH 3 with those in Ga-OH and other hydroxyls on zeolite. The structures of different Ga-CH 3 species were further determined by 2D 1 H- 13 C heteronuclear correlation NMR experiments, which were supported by theoretical calculations. The activation routes of C−H bond in methane were proposed on Ga/ZSM-5 zeolite.
研究领域:
化学
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材料科学
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DOI
高影响因子
Molecular Catalysis
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2023
·
IF 4.6
Xu Wu,Heqin Guo,Litao Jia,Yong Xiao,Bo Hou,Yongxiang Gao,Debao Li
δ-MnO 2 exhibits excellent activity for furfural oxidation to furoic acid under base-free conditions. However, its poor C H bond breaking capacity leads to lower conversion efficiency per unit mass catalyst than noble metal. Thus, a series of Ru-modified δ-MnO 2 (Ru x /δ-MnO 2 ) have been made to enhance its C H bond breaking ability. The result showed that the furfural conversion was greatly enhanced on Ru x /δ-MnO 2 due to the enhanced capability for breaking the C H bond. Especially for Ru0.25/δ-MnO 2 , whose conversion rate per unit mass was 18 times higher than δ-MnO 2 . The characterization results showed that the Ru species mainly existed as single atoms or clusters on Ru0.25/δ-MnO 2 and Ru0.5/δ-MnO 2 , while started to aggregate to RuO 2 nanoparticles on Ru1/δ-MnO 2 and Ru2/δ-MnO 2 . With the increase of Ru particles, the Ru's average oxidation state (AOS) decreased from +6 on Ru0.25/δ-MnO 2 to +4.74 on Ru2/δ-MnO 2. The Ru's TOF (intrinsic activity per Ru) was positively linearly related to the Ru's AOS. The electron-deficient Ru in Ru0.25/δ-MnO 2 can strongly adsorb the H atom of the C H of geminal diol intermediate and accelerate the breakage of its C H bond. As a result, Ru in the Ru0.25/δ-MnO 2 exhibited the highest TOF, which can even reach 29.85 mmol FF /mmol Ru /h.
研究领域:
化学工程
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材料科学
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产品关联
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
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2024
·
IF 15.7
Zhe Wang,Chunpeng Wang,Bing Lu,Zhirong Chen,Yong Wang,Shanjun Mao
Interface has often played significant role in the behavior of metal-based catalysts during various heterogeneous reactions. Herein, we reported a novel interfacial pathway for propane dehydrogenation on Pt-GaO x dual sites. The active ensemble, composing Pt particles and Ga 2 O 3 clusters, facilitates the facile dissociation of C–H bonds (energy barrier < 0.30 eV) through H-abstraction by O sites, coupled with alkyl stabilization on the Pt surface. Notably, the electronic perturbation of the Pt slab induces higher-lying O 2 p states at the interface, accompanied by a substantial density of states around fermi level. This is in stark contrast to the O species present in Ga 2 O 3 crystals or clusters alone, leading to an exceptionally strong affinity for H and a robust ability for C–H scission. The Pt/Ga-Al 2 O 3 catalysts prepared with Pt nanoparticles decorated by Ga oxide exhibit superior performance compared to Pt/Al 2 O 3 and PtSn/Al 2 O 3 catalysts. This insight into interfacial catalysis contributes to a broader understanding of the origin of the high catalytic efficiency observed in metal-based catalysts.
研究领域:
催化化学
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材料科学
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DOI
高影响因子
Catalysis Science & Technology
·
2024
·Vol. 14
·期 14
·4058-4067
·
IF 4.4
Yang You,Aijie Xu,Yao Lv,Lide Yang,Xuan Tang,Jie Tang,Yanglong Guo,Yao Cui,Wangcheng Zhan,Li Wang,Yun Guo,Sheng Dai
Complete oxidation of propane has drawn great attention in the fields of automotive emission control and volatile organic compound elimination. However, it is challenging to achieve high activity of this reaction due to the stability of propane. We here utilize a facile solvothermal method to construct tri-coordinated Al (AlIII) sites on the as-synthesized ST-Al2O3 support to alter the properties of supported Pt species. It is demonstrated that AlIII sites facilitate the dispersion and electron enrichment of supported Pt sites. Thus, Pt/ST-Al2O3 exhibits a superior activity toward complete propane oxidation, showing a 6.7-fold improvement in the turnover frequency over commercial Pt/Al2O3 catalysts. Meanwhile, Pt/ST-Al2O3 possesses a distinct reaction route originating from its stronger C–H and C–C cleavage capability, while having excellent activity not only in complete propane oxidation but also in the complete oxidation of other alkanes (CH4, C2H6, and n-C4H10). In addition, the AlIII construction strategy is successfully extended to more cases, e.g., Pd/ST-Al2O3 with higher Pd dispersion and electron density. This work provides a promising strategy for the control of the oxide support for advanced design and synthesis of alkane oxidation catalysts.
研究领域:
催化化学
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环境科学
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材料科学
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DOI
高影响因子
ACS Catalysis
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2025
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IF 13.1
Weina Yang,Yachao Wang,Yaxiong Wei,Guofeng Zhao,Weixin Huang,Cong Fu
Photocatalytic oxidative coupling of methane (OCM) offers a sustainable pathway for direct conversion of methane into value-added hydrocarbons, yet faces persistent challenges in balancing efficient methane activation with suppression of overoxidation. Here, we present a TiO2-based photocatalyst decorated with highly dispersed Ag–Co dual sites that achieves superior performance in continuous-flow OCM. The optimized AgCo–TiO2 system demonstrates a remarkable C2 hydrocarbon production rate of 1.7 mmol g–1 h–1 with 91% selectivity while maintaining stable operation for over 30 h. In situ spectroscopic analyses indicate that the introduced Co species induce mobile-charge imbalances, driving the directional transfer of photogenerated electrons and effectively suppressing electron–hole recombination. Coupled with Ag serving as a catalytic center, these effects synergistically enhance O2 activation, C–H bond cleavage, and selective C–C coupling, thereby contributing to the superior catalytic performance. This work provides valuable mechanistic insights into the photocatalytic OCM process, highlighting the pivotal role of precisely engineered charge transfer pathways in enabling efficient methane-to-C2 conversion.
研究领域:
光催化
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材料科学
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化学工程
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环境化学
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能量转换
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产品关联
DOI
高影响因子
ORGANOMETALLICS
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2020
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IF 3.804
Liangwei Zhang,Long Liu,Tianzeng Huang,Qizhi Dong,Tieqiao Chen
A palladium-catalyzed cyclobutanation of aryl sulfonates with strained alkenes has been developed. The methodology is featured to achieve the cleavage of both C–O and C–H bonds of phenol derivatives in one pot. Under the reaction conditions, in addition to reactive triflates, the relatively inactive tosylates and mesylates can also be transformed into the corresponding benzocyclobutanes in high yields. This reaction can be carried out in gram-scale experiments with a low loading of the palladium catalyst and is applicable to the cyclobutanative modification of bioactive molecules, highlighting its synthetic value in organic synthesis.
研究领域:
有机化学
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催化化学
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合成化学
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DOI
高影响因子
危险品化学品经营许可证（带存储）